ORAU TEAM

Dose Reconstruction

Project for NIOSH

 

Oak Ridge Associated Universities I Dade Moeller & Associates I MJW Corporation

Page 1 of 80

 New Total Rewrite Revision Page Change

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Document Title:

Rocky Flats Plant – Site Description

Document Number: ORAUT-TKBS-0011-2 

Revision: 01 

Effective Date: 02/01/2007

Type of Document: TBD

Supersedes: Revision 00 

Subject Expert(s): Susan Flack and Robert Meyer

Site Expert(s): N/A

Approval: Signature on File Approval Date: 01/25/2007

Robert Meyer, Document Owner

Approval: Signature on File Approval Date: 01/25/2007

John M. Byrne, Task 3 Manager

Concurrence: Signature on File Concurrence Date: 01/26/2007

Edward F. Maher, Task 5 Manager

Concurrence: Signature on File Concurrence Date: 01/25/2007

James P. Griffin, Deputy Project Director

Approval: Brant A. Ulsh Signature on File for Approval Date: 02/01/2007

James W. Neton, Associate Director for Science
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 2 of 80

PUBLICATION RECORD

EFFECTIVE 

DATE

REVISION 

NUMBER DESCRIPTION

01/10/2004 00 New Technical Basis Document for the Rocky Flats Plant – Site 

Description. First approved issue. Initiated by Robert Meyer.

02/01/2007 01 Approved Revision 01 revised in response to formal OCAS and 

ORAU comments. Includes additional incidents and occurrences 

post-1981. This revision addresses Worker Outreach comments as 

described in CT-0200 and CT-0204, in Section 2.4.5. Revised to 

consider attribution per ORAU direction and to respond to Union 

member comments. Incorporates NIOSH formal review comments. 

No further changes occurred as a result of formal internal review. 

Constitutes a total rewrite of document. This revision results in no 

change to the assigned dose and no PER is required. Training 

required: As determined by the Task Manager. Initiated by Robert 

Meyer.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 3 of 80

TABLE OF CONTENTS

SECTION TITLE

Acronyms and Abbreviations ...............................................................................................................

PAGE

5

2.1 Introduction ..............................................................................................................................7

2.1.1 Purpose........................................................................................................................8

2.1.2 Scope...........................................................................................................................8

2.2 Site Activities and Processes ...................................................................................................8

2.2.1 History and Mission ......................................................................................................8

2.2.2 Site Development .......................................................................................................10

2.2.3 Functional Areas.........................................................................................................11

2.2.3.1 Component Manufacturing ........................................................................... 11

2.2.3.2 Material Recovery and Purification............................................................... 14

2.2.3.3 Process Waste............................................................................................. 17

2.2.3.4 Research and Development......................................................................... 18

2.2.3.5 Plant Support ............................................................................................... 21

2.3 Releases to the Outdoor Environment.................................................................................... 22

2.3.1 Airborne Emissions.....................................................................................................22

2.3.2 Waterborne Emissions................................................................................................23

2.4 Accidents ...............................................................................................................................23

2.4.1 Accidents and Contamination Control.........................................................................25

2.4.2 Accidents Involving Plutonium ....................................................................................26

2.4.3 Tritium at Rocky Flats................................................................................................. 32

2.4.4 Accidents Involving Uranium ......................................................................................32

2.4.5 Accidents and Occurrences after 1981.......................................................................34

2.5 Site Closure and Decommissioning........................................................................................ 36

2.5.1 Building 371................................................................................................................37

2.5.2 Building 444................................................................................................................38

2.5.3 Building 707 Closure Project ......................................................................................38

2.5.4 771 Closure Project....................................................................................................38

2.5.5 Building 776/777 Cluster.............................................................................................39

2.5.6 Building 881................................................................................................................39

2.5.7 903 Pad and Lip .........................................................................................................39

2.5.8 Building 991................................................................................................................40

2.5.9 Other Buildings...........................................................................................................40

2.6 Attributions and Annotations .................................................................................................. 41

References ........................................................................................................................................42

Glossary ............................................................................................................................................46
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ATTACHMENT A, ROCKY FLATS BUILDINGS AND OPERATIONS................................................51

ATTACHMENT B, ROCKY FLATS JOB TITLES AND DESCRIPTIONS............................................ 63

ATTACHMENT C, PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS.................................. 66

ATTACHMENT D, OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY

FLATS PLANT .....................................................................................................70

LIST OF TABLES

TABLE TITLE

2-1 Plutonium release estimate distributions by event..................................................................

PAGE

32

2-2 Incidents involving radiation ................................................................................................... 36

C-1 Partial list of potential hazards associated with various job descriptions 

and locations..........................................................................................................................66

D-1 Operational accidents and incidents at Rocky Flats Plant ...................................................... 71

D-2 Incidents at Rocky Flats Plant reported in occurrence reports 1981–2005 ............................. 74

D-3 Incidents at Rocky Flats Plant reported in the quarterly total project 

summary reports, April 2003 to December 2005 .................................................................... 80

LIST OF FIGURES

FIGURE TITLE

2-1 Location of the Rocky Flats Plant in Colorado..........................................................................

PAGE

9

2-2 Rocky Flats Facility in 1990.................................................................................................... 12

2-3 Rocky Flats Facility in 1964.................................................................................................... 17

2-4 Rocky Flats Site waste disposal areas ................................................................................... 19

2-5 Plutonium air emission sources in 1988 ................................................................................. 24

2-6 Reported gross alpha radioactivity emissions from Rocky Flats plutonium 

facilities ..................................................................................................................................25

2-7 Sites of the major accidents at the Rocky Flats Plant............................................................. 27

2-8 Tritium air emission sources................................................................................................... 33

2-9 Uranium air emissions sources .............................................................................................. 35
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 5 of 80

ACRONYMS AND ABBREVIATIONS

AEC U.S. Atomic Energy Commission

AED aerodynamic equivalent diameter

ASRF Advanced Size Reduction Facility

BVO boiler vent operator

CAM continuous air monitor

CEDE committed effective dose equivalent

cfm cubic feet per minute

Ci curie

cm centimeter

cpm counts per minute

D&D decontamination and decommissioning

DAC derived air concentration

DOE U.S. Department of Energy

dpm disintegrations per minute

DU depleted uranium

ECM electrochemical milling operations 

EDE effective dose equivalent

EEOICPA Energy Employees Occupational Illness Compensation Program Act of 2000

EPA U.S. Environmental Protection Agency

ft foot

FY fiscal year

g gram

gal gallon

HEPA high-efficiency particulate air (filter) 

HEU highly enriched uranium

in. inch

kg kilogram

L liter

lb pound

m meter

mCi millicurie

MeV megavolt-electron

mi mile

min minute

mo month

mrem millirem

MSE molten salt extraction

mW milliwatt
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 6 of 80

MWM metal working manager

nCi nanocurie

NIOSH National Institute for Occupational Safety and Health

ORAU Oak Ridge Associated Universities

pCi picocurie

POC probability of causation

PPE personal protection equipment

PS process specialist

R&D research and development

RCT Radiation Control Technician

RFCA Rocky Flats Cleanup Agreement

RFETS Rocky Flats Environmental Technology Site

RFP Rocky Flats Plant

RMRS Rocky Mountain Remediation Service

SAAM special alpha air monitor

SNM special nuclear material

TBD technical basis document

TCA 1,1,1-trichloroethane

TLD thermoluminescent dosimeter

TPS Total Project Summary

TRU transuranic

TSR Technical Safety Requirements

U.S.C. United States Code

ZPPR Zero Power Plutonium Reactor

yr year

α alpha radiation

μCi microcurie

μg microgram

μm micrometer

§ section or sections
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 7 of 80

2.1 INTRODUCTION

Technical basis documents and site profile documents are not official determinations made by the 

National Institute for Occupational Safety and Health (NIOSH) but are rather general working 

documents that provide historic background information and guidance to assist in the preparation of 

dose reconstructions for particular sites or categories of sites. They will be revised in the event 

additional relevant information is obtained about the affected site(s). These documents may be used 

to assist NIOSH staff in the completion of the individual work required for each dose reconstruction.

In this document the word “facility” is used as a general term for an area, building, or group of 

buildings that served a specific purpose at a site. It does not necessarily connote an “atomic weapons 

employer facility” or a “Department of Energy [DOE] facility” as defined in the Energy Employees 

Occupational Illness Compensation Program Act [EEOICPA; 42 U.S.C. § 7384l(5) and (12)]. 

EEOICPA defines a DOE facility as “any building, structure, or premise, including the grounds upon 

which such building, structure, or premise is located ... in which operations are, or have been, 

conducted by, or on behalf of, the Department of Energy (except for buildings, structures, premises, 

grounds, or operations ... pertaining to the Naval Nuclear Propulsion Program)” [42 U.S.C. § 

7384l(12)]. Accordingly, except for the exclusion for the Naval Nuclear Propulsion Program noted 

above, any facility that performs or performed DOE operations of any nature whatsoever is a DOE 

facility encompassed by EEOICPA.

For employees of DOE or its contractors with cancer, the DOE facility definition only determines 

eligibility for a dose reconstruction, which is a prerequisite to a compensation decision (except for 

members of the Special Exposure Cohort). The compensation decision for cancer claimants is based 

on a section of the statute entitled “Exposure in the Performance of Duty.” That provision [42 U.S.C. § 

7384n(b)] says that an individual with cancer “shall be determined to have sustained that cancer in the 

performance of duty for purposes of the compensation program if, and only if, the cancer ... was at 

least as likely as not related to employment at the facility [where the employee worked], as 

determined in accordance with the POC [probability of causation1

As noted above, the statute includes a definition of a DOE facility that excludes “buildings, structures, 

premises, grounds, or operations covered by Executive Order No. 12344, dated February 1, 1982 

(42 U.S.C. 7158 note), pertaining to the Naval Nuclear Propulsion Program” [42 U.S.C. § 7384l(12)]. 

While this definition contains an exclusion with respect to the Naval Nuclear Propulsion Program, the 

section of EEOICPA that deals with the compensation decision for covered employees with cancer 

[i.e., 42 U.S.C. § 7384n(b), entitled “Exposure in the Performance of Duty”] does not contain such an 

exclusion. Therefore, the statute requires NIOSH to include all occupationally derived radiation 

exposures at covered facilities in its dose reconstructions for employees at DOE facilities, including 

radiation exposures related to the Naval Nuclear Propulsion Program. As a result, all internal and 

external dosimetry monitoring results are considered valid for use in dose reconstruction. No efforts 

are made to determine the eligibility of any fraction of total measured exposure for inclusion in dose 

reconstruction. NIOSH, however, does not consider the following exposures to be occupationally 

derived:

] guidelines established under 

subsection (c) ...” [42 U.S.C. § 7384n(b)]. Neither the statute nor the probability of causation

guidelines (nor the dose reconstruction regulation) define “performance of duty” for DOE employees 

with a covered cancer or restrict the “duty” to nuclear weapons work.

• Radiation from naturally occurring radon present in conventional structures

• Radiation from diagnostic X-rays received in the treatment of work-related injuries

 

1 The U.S. Department of Labor is ultimately responsible under the EEOICPA for determining the POC. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 8 of 80

2.1.1

The purpose of this TBD is to provide a Rocky Flats Plant (RFP) profile that contains technical basis 

information used by the Oak Ridge Associated Universities (ORAU) Team to evaluate the total 

occupational dose for EEOICPA claimants. This section provides information on RFP facilities and 

operations.

Purpose

2.1.2

RFP operations played an important role in the U.S. nuclear weapons program. Operations included 

production of fissionable material components. This TBD contains supporting documentation to assist 

in the evaluation of worker dose from RFP operations and processes. Additional guidance is found in 

OCAS-IG-001, External Dose Reconstruction Implementation Guideline (NIOSH 2002a) and OCASIG-002, Internal Dose Reconstruction Implementation Guideline (NIOSH 2002b). 

Scope

The methods used to measure radiation exposure to workers have evolved since the beginning of 

RFP operations. An objective of this TBD is to provide supporting technical data to evaluate the total 

RFP occupational dose that can reasonably be associated with worker radiation exposure as covered 

under EEOICPA. This dose includes occupational external and internal exposure in RFP facilities, 

RFP occupationally required diagnostic X-ray examinations, and onsite exposure to RFP 

environmental releases as required by ORAU guidance (ORAUT 2006a). 

This TBD describes RFP facilities and processes. Other TBDs in this Site Profile provide historic 

information related to worker medical X-ray, internal, and external exposures, and environmental data 

for use if outdoor monitoring data are unavailable. Attachments related to those TBDs provide 

detailed data and tables for dose reconstructors.

2.2 SITE ACTIVITIES AND PROCESSES

A comprehensive history of the Rocky Flats Plant was prepared as part of Rocky Flats health studies 

conducted by the Colorado Department of Public Health and Environment during the 1990s (see 

ChemRisk 1992, 1994a,b). Information in this TBD section is from these 1990s reports except as 

otherwise noted. 

2.2.1

The U.S. Atomic Energy Commission (AEC) announced its decision on March 23, 1951, to build the 

Rocky Flats Plant in Colorado (see Figure 2-1). Groundbreaking occurred in July 1951 for what is 

now Building 991. In general, the primary mission and activities at the Plant remained essentially the 

same from the time the Plant opened until 1989, when DOE suspended plutonium operations. The 

Rocky Flats Plant had two major missions – production of plutonium triggers (or “pits”) for nuclear 

weapons and processing of retired weapons for plutonium recovery. From the beginning the Plant 

was a manufacturing facility. Plutonium triggers are components of fission bombs, used to initiate the 

second-stage fusion reaction in hydrogen bombs. The Plant received plutonium from production sites 

(the Savannah River and Hanford Sites) and from retired warheads and residues. Parts were formed 

and machined from plutonium and uranium, and beryllium, stainless steel, and other nonradioactive 

materials (ChemRisk 1992).

History and Mission

In 1984, the site was proposed as a Superfund site and, in 1989, it was included on the National 

Priorities List for cleanup of environmental contamination. In December 1989, DOE suspended 

plutonium processing to review and upgrade the Plant’s safety systems. EG&G, Inc., assumed 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 9 of 80

Figure 2-1. Location of the Rocky Flats Plant in Colorado. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 10 of 80

operation of the site on January 1, 1990, working toward the resumption of operations in the 

plutonium buildings. With the President’s 1992 announcement of cancellation of the W-88 Trident 

Warhead Program, the Rocky Flats production mission ended permanently. In 1993, the Secretary of 

Energy formally announced the end of nuclear production at Rocky Flats. In 1994, the last defense 

production-related shipment was sent from Building 460. Remediation was completed at the former 

Rocky Flats Plant site in late 2005.

There have been only three basic pit designs since the beginning of Plant operations, with 

manufacturing of the first two designs phased out within the first 5 yr of production. The first two 

designs built at Rocky Flats were solid units made mostly of uranium. Design changed around 1957 

to focus primarily on plutonium (ChemRisk 1992). 

2.2.2

The following paragraphs describe the chronological development of RFP facilities and operations. 

Figures at the end of this section show the location of these facilities as they were constructed. 

Attachment A lists facility functions by building.

Site Development

1951–1954

Groundbreaking for the first permanent buildings at the Rocky Flats Plant began in July 1951 for what 

is now known as Building 991. Later that year, construction began on Buildings 771, 444, and 881. 

By April 1952, production operations reportedly had begun, but no production or shipment details are 

available for 1952 or the first part of 1953. At the beginning of 1953, some of the onsite utility facilities 

were still incomplete; water came from Boulder in tank trucks, and a locomotive brought to the site 

provided steam heat. Nevertheless, the first products were completed and shipped that year. By 

1954, the Plant was fully operational, with initial construction essentially complete with about 

700,000 ft2 of building space. Employment grew steadily from 133 people in 1951 to 3,101 in 1963.

Originally, the Plant had four operational areas – A, B, C, and D Plants –- identified according to four 

primary types of work. The A Plant included Building 444 operations, which involved the fabrication of 

depleted uranium (DU) parts. Later known as Building 881, the B Plant recovered enriched uranium 

and manufactured enriched uranium components. The C Plant (later Building 771) housed plutonium 

operations, and the D Plant in Building 991 was the center of final product assembly operations. 

There were large spans of meadow between the areas, with gravel roads connecting them. Very few 

people had clearances to get into more than one building, and most employees had no idea what 

occurred in areas other than their own. Plant employees were bussed from the front gate to their 

buildings, because personal vehicles were not allowed on the site. 

1955

A major facility expansion began in 1955, referred to as Part IV construction.

1956–1957

This period saw the construction of Buildings 447, 776, 777, 883, 997, 998, and 999 and the 

expansion of Buildings 444, 881, and 771. These additions were directly related to the change of the 

weapon concept to a hollow unit and anticipated production increases. A few years later, roughly 

coincident with the onset of the Cold War, RFP became the primary manufacturer of pits under the 

single-mission concept. The result was a dramatic rise in production at the Plant in the 1960s. By 

1964, the workforce reached a level of around 3,000 people that lasted for about 15 years. 

1967–Early 1970s

Buildings 559, 440, 707, 750, and 865 were constructed.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 11 of 80

Late 1970s–2006

DOE built Buildings 371 and 460 during this period. The period showed a significant upturn in Rocky 

Flats employment, with a peak at 5,990 in 1984.

By 1990, total building space had grown to approximately 2.5 million ft2

. Figure 2-2 shows the 1990 

RFP layout, including the structures identified in the previous paragraphs. 

By late 2005, remedial action was complete at the former Rocky Flats Plant.

2.2.3

Rocky Flats operations included the following functional areas:

Functional Areas

• Component Manufacturing and Assembly

• Material Recovery and Purification

• Research and Development (R&D)

• Waste Processing

• Plant Support

To manufacture a fissionable product, RFP developed facilities, equipment, and personnel to conduct 

precision metalworking and to assemble fissionable and nonfissionable materials. Key nonfissionable 

components were made of beryllium, aluminum, and stainless steel. 

Early work at the Plant involved both 235U and 239Pu as fissionable materials. Enriched uranium 

contract work transferred to the Oak Ridge Reservation in 1964. Americium-241 recovery did not 

start until 1957, functioning as a step in the plutonium recovery process and producing a marketable 

product. Beryllium was not used in full-scale production operations until 1958. Stainless-steel

component work began in 1966. Stainless-steel operations (known as the "J Line”) took place in 

Building 881 until 1984, when they moved to Building 460. 

2.2.3.1 Component Manufacturing

When the A Plant (Building 444) started operations in 1953, it was devoted entirely to DU 

manufacturing. Operations included casting and machining of components. While no details are 

available, processing of DU is not generally considered to be a significant hazard from either an 

external (photon) or internal (alpha-emitter) perspective. RFP originally received DU from Paducah, 

Kentucky, and later as feed material from the Feed Materials Production Center in Fernald, Ohio, as 

ingots in sealed cans. While TBD reviewer comments indicate that Paducah was processing recycled 

uranium beginning in 1953, available Rocky Flats records do not indicate whether fission product or 

transuranic (TRU)-contaminated uranium was processed at Rocky Flats.

Enriched uranium operations occurred in B Plant (Building 881) and initially involved a heavy 

workload. The basic operations involved casting and machining. The components were solid pieces 

of uranium, machined to particular shapes, which were assembled with plutonium, stainless-steel, and 

DU components in D Plant. 

With development of new designs, the revised concept required a significant amount of rolling and 

forming of depleted and enriched uranium, and space in existing facilities became inadequate. 

Building 883 was built to handle the rolling and forming of uranium. DU was cast in Building 444, but 

was shipped to Building 883 to be heated and rolled into sheets from which blanks were cut and 
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Figure 2-2. Rocky Flats Facility in 1990. 
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formed to the required shape. The shaped pieces were shipped back to Building 444 to be turned, 

trimmed, and polished. In some cases, the component was coated with protective materials. 

Building 883 was designed with two functional areas to prevent cross-contamination; the B side 

handled enriched uranium, and the A side rolled and formed DU. The Plant was so pressed to begin 

production of the new type of weapon components that operations began in Building 883 before the 

roof was completed. To prevent emissions from these early operations and to protect machinery and 

materials from the elements, enclosures were placed around the process equipment. Details 

concerning early ventilation and other worker protection systems during this period were not found in 

the available literature.

R&D of DU-niobium alloys involved an electron-beam furnace. Alloying work began in 1966, although 

full-scale production did not occur until the early 1970s. An arc furnace installed in the mid-1970s 

provided the capability to produce DU-niobium alloys. This furnace melted elements such as 

zirconium and niobium more effectively than induction casting furnaces, thereby creating a more 

homogenous alloy casting. 

In the early 1960s, Building 881 was idle while the enriched uranium areas were decontaminated and 

decommissioned. Conversion to accommodate stainless-steel operations began in 1966. Machining 

of DU continued in Building 444. In 1964, the B side of Building 883 was converted to beryllium rolling 

and forming. 

After the Oak Ridge Reservation took over enriched uranium operations in 1964, it supplied RFP with

finished uranium components for incorporation in final pit assemblies. RFP still received site returns 

that contained enriched uranium components. The Plant processed those components with a spray 

leaching process to remove external plutonium contamination, and returned the oralloy parts to Oak 

Ridge for reprocessing. Oralloy leaching operations were originally in Building 881, but were moved 

to Building 771 in the mid-1960s. The oralloy leaching process remained in Building 771 through 

1989 (ChemRisk 1992).

Early during facility operations, C Plant (Building 771) housed essentially all plutonium manufacturing 

and recovery. In the early years, plutonium metal was machined in a dry state (i.e., without oils, using 

only carbon tetrachloride as a coolant), with as little machining as possible. Handling the dry material 

required extra care to prevent spontaneous combustion. Plutonium components were cast, pressed 

into shapes, minimally machined to true them, and plated with cadmium, which enabled handling with 

reduced personnel exposure to neutrons and alpha particles. The first weapons were designed such 

that they were to be armed (final assembly) in the aircraft on the way to the target. The protective 

coating grounded the parts against static electricity that might be generated while handling them in the 

field. The coating changed to nickel within a few years, using a process that employed nickel 

carbonyl. The use of nickel carbonyl lasted at least into the late 1960s, although its use in later years

was reduced due to design changes that enabled remote arming. 

Building 776 machining operations (also involves Buildings 771, 777, 881, 460, 991, 707, and 

444)

Higher-volume machining of plutonium began in 1958, with new operations in Building 776 using Shell 

Vitrea, a cutting oil, followed by washing with carbon tetrachloride. Building 776 housed a centralized 

collection and separation point, and the solid and liquid fractions were sent separately to Building 771. 

In Building 771 most of the carbon tetrachloride was distilled from the oil, and the plutonium cuttings 

were recovered from the solids. At that time, Building 777 was the focal point for assembly 

operations. Facility staff members were unable to develop a satisfactory method for handling spent 

oils and residual solvents, which were placed in storage barrels outdoors to the east of the Plant. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 14 of 80

Buildings 776 and 777 went into service in 1958 to handle the increased plutonium workload, and 

Building 771 undertook recovery operations. Building 776 performed plutonium machining; Building 

777 handled assembly operations. Building 991 was used for storage and R&D, although it was 

several years (records indicate 1960) before all assembly operations had left the building. In 1969, a 

major fire in Buildings 776 and 777 resulted in some operations moving to other buildings. The 

machining and foundry operations in the fire-damaged areas of Building 776 became part of the 

operations in the new 707 assembly building. Those operations remained in Building 707, and solid 

waste treatment operations and size reduction moved into Building 707 after Building 776 returned to 

operation in 1972. (Building 776 in 1972 was being used for waste storage and waste size reduction.)

Final assembly of the early products was initially a relatively simple operation. The original final 

assembly building was D Plant, now known as Building 991. Later, the hollow-core weapons design 

involved more assembly complexity. As a result, Building 777 in 1957 began to provide assembly 

facilities. Operations involved drilling, welding, brazing, turning, and polishing. Building 707 began 

final assembly operations shortly after the 1969 fire, which shut down Buildings 776 and 777. Final 

assembly operations occurred in Building 707 through 1989. 

Stainless-steel operations, the J Line, began in Building 881 in 1966 and remained there until the 

completion of Building 460 in 1985. Stainless-steel operations from Building 881 and some 

operations from Building 444 were consolidated in Building 460 at that time. A significant portion of 

the stainless-steel work was the fabrication of empty tritium reservoirs. The reservoirs were later filled 

with tritium gas under high pressure at the Savannah River Site.

In 1957, the new weapon design required beryllium components. There had been some beryllium 

operations in Building 444 in preparation for regular pit production, and in 1958 beryllium operations 

became a significant portion of RFP activities. The components manufactured in Building 444 no 

longer went directly to the Pantex Plant. Rather, they were incorporated in the final assembly 

operations in Building 777. The DU workload decreased significantly as beryllium use increased 

(ChemRisk 1992). 

Beginning in 1952, thorium was used onsite in quantities small enough that effluents were not 

routinely analyzed for thorium. Thorium quantities varied from as little as none to as much as 238 kg 

in a given month. The principal use was fabrication of metal parts from natural thorium metal (232Th) 

and from various thorium alloys. Thorium oxide might have been used as a mold-coating compound 

in limited experiments. Thorium compounds were used in analytical procedures. In addition, twice 

between 1964 and 1969, thorium “strikes” were performed to remove gamma-emitting 228Th from 233U 

metal needed for fabrication of test devices. The strikes involved a fluoride precipitation and filtration 

process using natural thorium. Photon radiation from 228Th decay products would have been 

monitored by standard gamma dosimetry badges in use at the Plant. In addition, thorium was used 

as a stand-in for plutonium or uranium components in development programs (ChemRisk 1992).

2.2.3.2 Material Recovery and Purification

Manufacturing produced wastes, which consisted of fissionable and nonfissionable materials, 

associated lubricating and cleaning compounds, and other materials such as rags, slags, clothing, 

tools, and paints. Wastes were stored in barrels in the 903 area just outside the main fence. In the 

late 1960s, waste oils were eventually treated by fixation in concrete and shipped off the site for 

burial. Cleanup of the 903 area resulted in some potential for worker exposure to airborne plutonium 

from disturbance of contaminated soil.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 15 of 80

Plutonium Recovery and Purification

When Building 771 became operational in 1953, operations included plutonium recovery (from 

weapons manufacture and later from weapons recycle) and purification, and plutonium component 

manufacturing. Plutonium operations patterned after Los Alamos plutonium facility work began in the 

spring of 1953. Only one "Chem Line" was in operation; it had the capacity to produce plutonium 

“buttons” of approximately 300-g mass. Later, in 1955, an "East Chem Line" started, with the 

capability to produce 2-kg buttons. Eventually, operational capacity reached 12 kg per day. In 1965, 

an expanded production area added five dissolution lines, increasing plutonium recovery by a factor of 

20 over that of the original line (ChemRisk 1992). In 1968, the decision was made to replace Building 

771 recovery operations. Groundbreaking took place in 1973 for what was to become Building 371. 

The new facility was plagued with problems from the onset of construction, and delays prevented cold 

startup before 1981. Design flaws resulted in the shutdown of Building 371 chemical processing in 

1985 before full-scale operation occurred. 

Originally, plutonium at Rocky Flats came from Hanford as plutonium nitrate in small stainless-steel 

flasks packaged in cylindrical steel carrying cases. The nitrate was vacuum-transferred into a vessel 

in which plutonium dioxide was precipitated. Chemical reduction converted the dioxide to metal 

buttons. Later, plutonium was received from Hanford in the form of buttons. Occasionally, plutonium 

nitrate feed was received from the Oak Ridge Reservation. In 1959, these shipments were reduced, 

and most of the plutonium feed to recovery and purification operations became recycled material from 

site returns and the foundry, or waste products from the recovery operation. Some plutonium that 

went through the system at this time came from outside sources in the form of plutonium dioxide. 

Later shipments of plutonium consisted of metal buttons from the Savannah River Site. 

RFP produced components from other metallic radionuclides on a limited basis for incorporation in 

pits for special-order operations. The inclusion of these radionuclides (237Np, 241Am, 238Pu, and 244Cm) 

as tracers into the makeup of the pits enabled research elsewhere. The Special Recovery area 

processed the plutonium tracer materials. Eventually, leftover tracer materials had to be removed 

from the plutonium streams, which became part of Special Recovery operations. Special Recovery 

operations included the Oralloy and Part V Leaching lines, in which surface impurities were removed 

from enriched uranium and plutonium components.

The recovery process was often described in terms of functional divisions – "fast" and "slow" recovery 

operations. The fast cycle processed plutonium nitrate solution, turning the liquid to a solid (powder) 

and then to metal. The slow cycle received materials with higher concentrations of impurities 

(requiring a greater degree of preprocessing before entering the fast cycle metal conversion process). 

Before the implementation of the molten salt extraction (MSE) process in 1968, almost all plutoniumbearing materials went through slow recovery operations. These materials had to be converted to 

plutonium nitrate via the slow cycle and then introduced into the fast cycle line for conversion to a 

solid and reduction to metal. Since the introduction of the MSE process in 1968, some of the 

essentially pure plutonium metal, such as the metal from site returns, went through MSE to remove 

americium ingrowth and then directly to plutonium foundry operations in Building 777 for casting and 

subsequent processing into plutonium components. As a result, slow cycle recovery received such 

materials as effluents and waste products from the fast cycle, rags, paper goods, sweepings, and 

other wastes. It no longer processed the purer forms of plutonium.

Slow recovery operations involved a variety of processes. For example, combustible residues such 

as plastic bags and Kimwipes were incinerated to reduce material bulk and to convert the plutonium 

into an oxide form. Before 1960, dissolution was followed by a solvent extraction step that used 

tributylphosphate as the solvent and dodecane as the diluent. The solvent extraction was followed by 

cation exchange. Around 1960, solvent extraction was eliminated from the recovery process line 
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because the materials going through the recovery process were becoming more and more varied 

(ChemRisk 1992).

Uranium Recovery and Purification

Building 881 was built in 1952, and housed enriched uranium component manufacturing, including 

machining and fabrication of parts. When the chemical recovery line began enriched uranium 

recovery from metal residues created in the manufacturing processes in 1954, Building 881 housed all 

enriched uranium operations, from casting to forming, machining, assembly, recovery, and 

purification. The raw material came from the Oak Ridge Reservation, primarily in the form of hockeypuck-size buttons of pure metal. 

Uranium recovery operations in Building 881 were modeled after processes developed during and 

after World War II at Los Alamos National Laboratory and the Oak Ridge Reservation. The 

Building 881 process was similar to the 1950s plutonium recovery process that included solvent 

extraction. Uranium recovery had fast and slow sides and involved similar chemistry, but 

dibutylethylcarbutol was used as the solvent, rather than the tributylphosphate and dodecane used as 

the solvent and diluent, respectively, in plutonium recovery. Overall, the basic plutonium and uranium 

recovery operations were similar (ChemRisk 1992). 

Americium Recovery

There was a pressing need to deal with the americium in the plutonium handled at RFP, because ingrowth of 241Am from 241Pu decreases the effectiveness of the plutonium and creates a gamma 

exposure problem. The Plant had a backlog of americium-containing sludge generated from a 

plutonium recovery process. As a result, in 1957 an americium line began operation in Building 771. 

From the late 1950s until the late 1970s, americium was recovered and purified at the Plant for sale. 

The demand for americium declined in the late 1970s, and the americium removed in the plutonium 

purification process went to Building 774 for processing as a radioactive waste. Information for this

period concerning the chemical form of extracted 241Am was not discovered during this TBD review. 

Americium operations were limited to MSE operations needed to purify plutonium metal.

In 1962, a slight change was made to the ammonium thiocyanate process by adding oxalate 

precipitation and calcination steps, which resulted in an americium oxide product that was preferred 

because of its stability. The process during this period was cumbersome, resulted in a 

disproportionate quantity of waste solutions, and created personnel alpha-contamination exposure

problems due to required manual operations and maintenance. 

In 1967, the MSE process became the feed source for americium purification. In MSE, molten 

americium-bearing plutonium came into contact with molten NaCl-KCl-MgCl2 salt. Oxidation-reduction 

reactions with the salt separated the americium from the plutonium by equilibrium partitioning. There 

were alpha-contamination personnel exposure problems associated with the hydroxide precipitation 

step, and in 1973 it was replaced with a cation-exchange procedure. The entire process underwent 

another major change in 1975, when the ammonium thiocyanate steps were eliminated and the 

americium was recovered from the anion effluent by oxalate precipitation with subsequent calcination 

to form the more stable oxide.

After 1976, MSE salts were sent to a “salt scrub” process rather than to americium purification. (A salt 

scrub removes americium and plutonium from MSE salts.) Salt scrub made a "scrub alloy" of 

americium, plutonium, and gallium that was shipped to Oak Ridge for further processing. Americium 

recovery and purification operations shut down in 1980, and work was limited to that required to 

extract americium from plutonium metal in site returns (ChemRisk 1992).
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2.2.3.3 Process Waste

When Building 774 was built in 1952, its primary purpose was to support Building 771 by treating its 

radioactive aqueous waste. The general mission of the waste operations was to reduce the volume of 

wastes. Liquids transferred to Building 774 were subjected to pH adjustment and sent through a 

precipitation step to remove radionuclides. The resulting slurry was sent to vacuum filters. The solids 

removed from the filters were combined with cement or another solidifying agent and shipped to longterm storage as TRU mixed waste. The aqueous waste from this first stage went through the process 

again. Before 1973, aqueous wastes from this process went to either the solar evaporation ponds or 

the "B" series of holding ponds, depending on the concentrations of radioactivity. Maintenance and 

eventual cleanup of the solar ponds introduced potential worker exposure scenarios (Meyer and Till 

1999).

Around 1965, an evaporator was installed in Building 774 to treat liquids that had accumulated in the 

solar evaporation ponds. Water and volatiles evolved from the evaporation process were discharged 

to the atmosphere. The concentrate from the evaporator was fed to a double drum dryer, on which 

the salt solution dried for removal by a scraping blade. Water vapor and volatiles from the dryer went 

through a scrubber and demister before venting to the stack, with the liquids from the scrubber and 

demister returning to the aqueous treatment process. The evaporator was removed from service in 

1979, and liquids from the second stage of treatment and the solar ponds were transferred to 

Building 374. Figure 2-3 shows the locations of these ponds.

Figure 2-3. Rocky Flats Facility in 1964. 

Building 374 went into operation in 1978 as an integral part of the new plutonium recovery facility, 

Building 371. Building 374 was designed to handle wastes generated in Building 371. The processes 

used in Building 374 were essentially the same as those used in Building 774, with more efficient 

equipment. Building 374 was also designed to provide greater safety of operation through improved 

containment, control systems, and separation of workers from operations.
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While most hazardous and radioactive wastes were shipped off the site for disposal, approximately 

178 inactive waste sites existed within the Plant boundaries as production operations were completed 

in the late 1980s, some of which had been the sites of burial, incineration, and land application 

(ChemRisk 1992). 

Liquid sanitary waste operations were kept separate from the liquid process waste operations to 

prevent contamination of the sanitary waste streams. Holding tanks upstream from the treatment 

plant were sampled to check for plutonium contamination. Standard waste treatment was provided. 

Final disposition of sludges has changed over the years. From 1954 to 1968, 100 tons of sanitary 

sludges were disposed of in onsite trenches (T-2 through T-8). At that time, some floor drains in the 

manufacturing buildings were not isolated from the sewage treatment plant, and the sanitary sludge 

became contaminated with uranium and plutonium. A second landfill that opened in 1968 received 

sludges until 1969. At that time, the sludges were declared low-level radioactive waste and shipped 

off the site to approved disposal sites.

There were instances of onsite burial of contaminated materials, most notably soils that were 

contaminated as a result of the 1969 fire and other soils excavated during cleanup of the laundry 

waste outfall formerly located on the north side of Building 771. In the early years of Plant operation, 

laundry waste was discharged directly to Walnut Creek. The released water met then-current 

standards for concentrations of plutonium and uranium. On December 21, 1973, the release of 

laundry waste to Walnut Creek ended.

The original RFP landfill, on the south side of the plant, opened in 1952 and closed in August 1968. 

An incinerator was in operation at that time, in Facility 219 on the west access road. With a few 

exceptions, nonradioactive combustible waste was burned in the incinerator and the resultant ashes 

were buried adjacent to the incinerator. It is estimated that fewer than 100 g of DU were incinerated 

in general plant waste between 1952 and 1968 (ChemRisk 1992).

Figure 2-4 shows the locations of waste disposal areas at the site.

2.2.3.4 Research and Development

Rolling of enriched uranium foil was conducted in 1964 in the northeast comer of the Plant garage, 

Building 331. Interviews suggest that this area was also used for the development of DU and uranium 

alloy casting techniques, using electron beam heating, and uranium coating studies until Building 865 

came on-line in 1970 (ChemRisk 1992). 

In the mid-1960s, R&D work became a larger part of the activities at the Plant, as Buildings 779, 559, 

and 865 were constructed. Much of this work focused on examining site returns to determine the 

effects of time and field conditions on the weapons, including corrosion and other forms of 

deterioration. 

Building 779, a plutonium R&D facility, was constructed in 1965. Its purpose was to study the 

chemistry and metallurgy of plutonium and its interactions with other materials. In addition, 

Building 779 housed efforts to develop improvements to manufacturing processes, to find new ways 

to recover plutonium and associated actinides, and to better understand the aging characteristics and 

shelf lives of RFP products. 

Building 865 began operations in 1970. It served as an R&D facility primarily for manufacturing 

processes using uranium and beryllium. The work involved metalworking and metallurgy techniques. 

The metallurgical operations involved the development of alloys and alloying processes, and 
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Figure 2-4. Rocky Flats Site waste disposal areas. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 20 of 80

fabrication of prototype hardware. Metalworking operations include melting and casting, forging, 

press forming, extrusion, drawing, rolling, diffusion bonding, hydrospinning, swaging, cutting and 

shearing, and heat-treating. In addition, glovebox operations involved high-purity beryllium powder 

and machining operations that generally involved nonfissionable materials.

After 1964, Building 881 became a multipurpose facility for R&D, analytical work, Plant support, and 

administrative offices. Operations included analytical laboratories, generation of chemical standards, 

activities to machine small parts for weapons and energy generation research, gold plating of parts, 

assembling microscopic parts, and large machining operations. The Special Weapons Projects group 

was involved in the development of engineering prototypes and full-scale models for military training. 

Recovery Technology activities included materials development, process instrumentation and control, 

and equipment design and development. The Waste Chemistry group supported engineering and 

development of onsite waste treatment processes, and the Joining Technology group conducted 

operations to join non-nuclear metals including beryllium, in some cases using brazing alloys including 

nickel. Other operations in Building 881 included Nondestructive Testing, Records Management and 

Storage, and maintenance shops and activities.

Explosive bonding experiments occurred at the explosive forming area near Building 993 from 1965 

until approximately 1968. The experiments were designed to explosively bond together flat plates of 

stainless-steel and uranium alloy using high explosive. The explosive events took place below grade. 

No information was identified to indicate whether releases to the environment occurred during these 

tests, which typically involved relatively small amounts of explosives (192 g of 40% dynamite were 

routinely used in the bonding tests). While available records do not indicate the isotopic composition 

of uranium used in these tests, the tests were designed to examine the chemical/physical 

characteristics of the explosive bonding process, and it is unlikely that enriched uranium would have 

been used in such tests. 

Work for Others

The Plant conducted Special Order work for other facilities in the weapons complex, the Department 

of Defense, or other agencies. Most Special Order work did not involve materials other than types 

used in production activities. The tracer work noted above was an exception. Neptunium-237 tracer 

work associated with uranium and plutonium components took place in Buildings 771 and 881. Exact 

dates of production and later recovery of these tracers (from recycled materials) are not readily 

available – such work was occurring at Rocky Flats from the mid-1960s to the late 1970s, based on 

interpretation of available information. There was considerable effort devoted to keeping tracer 

materials separate from the regular production material streams, and Special Recovery operations 

focused on recovering the materials. 

For the Zero Power Plutonium Reactor (ZPPR) project, RFP manufactured approximately 4,000 

stainless-steel-clad fuel elements consisting of plutonium, molybdenum, and uranium during 1967 and 

1968. The Plant manufactured the fuel rods for installation in the reactor at Argonne National 

Laboratory – West. These elements were made by alloying uranium and molybdenum in 

Building 444. The uranium-molybdenum alloy was sent to Building 771, where it was alloyed with 

plutonium by casting into plates of various sizes. The “ternary alloy” plates were clad in stainlesssteel envelopes in Buildings 776 and 777 and sealed by welding. The plutonium used in this project 

originated in the United Kingdom and contained a higher percentage of 240Pu than most Rocky Flats 

plutonium, so the project took care to keep it separate from other plutonium recovery and waste 

streams. ORAUT (2006b) provides additional details concerning the radionuclide makeup of ZPPR

fuel. 
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During the late 1970s and early 1980s, RFP made thousands of calorimeter plates from DU for 

Sweden, Harvard University, and Brookhaven National Laboratory. In a large project that involved 

processing hundreds of tons of DU in Building 883 in the mid-to-late 1980s, the Plant made armor 

plates for the M1A1 tank. In the mid-1980s, the U.S. Army developed an advanced type of layered 

Burlington armor that incorporated DU. 

RFP was involved in "Project Plowshare,” the effort to develop technology for using nuclear 

explosives for peaceful applications, such as excavation and uncovering of deep mineral deposits. 

This involvement lasted from 1959 to the mid-1970s. An objective of the project was to use as little 

fissionable material as possible to limit fission product production. 

2.2.3.5 Plant Support

The Plant had a number of support organizations, including administration and finance, utilities, 

facilities management, and health and safety personnel. The Plant also had some unusual support 

organizations, including the Criticality Laboratory (or Nuclear Safety Group), which was responsible 

for identifying and directing control of the potential for criticalities in Plant activities. Another unique 

support function was provided by the Filter Testing group formed in 1979, which performed pre- and 

postinstallation testing of the high-efficiency particulate air (HEPA) filters used in ventilation exhaust 

systems and of personnel respirators.

The Nuclear Safety Group was at the Plant beginning in 1953. At that time, the group did not have its 

own facility. In the early years, the group performed its work in the areas in which production 

materials were handled. The in situ experiments were always subcritical; neutron count rates were 

observed as criticality was approached (ChemRisk 1992).

In more recent years, the Nuclear Safety Group conducted its work in Building 886, which was 

commissioned in 1965. Since that time, this group conducted about 1,600 critical mass experiments 

using enriched uranium, and plutonium, in solutions (800 tests), compacted powder (300), and 

metallic forms (500). After 1983, criticality experiments were not conducted with solid materials; they 

were conducted primarily with uranyl nitrate solutions, which were reused. Building 886 housed the 

Critical Mass Laboratory, offices, and a small electronics and machine shop. 

Approximately half of the 1,600 criticality experiments in Building 886 achieved criticality. 

Experiments in the RFP laboratory generally involved power levels of no more than 10 mW, for no 

more than an hour. Approximately six high-power experiments involved between 10 and 100 times 

the power of typical tests. Using a conversion factor of 3 × l016 fissions per megawatt-second, this 

power level and duration corresponds to a maximum of 1.01 × 1012 fissions from a typical RFP 

criticality experiment and a maximum of 1 × 1014 fissions from a high-power experiment. Records 

indicate that there were no incidents at Rocky Flats in which the power level of fissionable material 

became uncontrollable. The experiments were controlled by bringing the materials slowly to nearcriticality, monitoring the neutron flux to observe the reaction state. There is no indication in the 

available records that gamma exposure or exposure to created fission products was a worker 

exposure problem during these experiments.

Beginning in 1965, airborne effluents from Building 886 were sampled for radioactive particulates. 

Between 1971 and 1989, reported plutonium effluents from Building 886 were no more than 5% of the 

site total (in 1978) and enriched uranium emissions were no more than 10% of the site total (in 1976).

Release of waterborne radioactivity from the Critical Mass Laboratory was limited to several incidents 

involving spills of uranyl nitrate solution (enriched uranium) and disposal of wastewater from such 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 22 of 80

activities as mopping floors. The Laboratory floors were sealed and bermed to contain such spills. 

From the late 1960s to the late 1970s, wastewater from activities such as mopping was collected and 

periodically transferred to the solar evaporation ponds, after sampling and analysis indicated that the 

enriched uranium content of the water was much less than 1 g/L. 

The Health Physics Laboratories, located in Building 123, performed analyses of personnel 

dosimeters and all airborne sample analyses, including stack samples and general room air samples. 

The laboratories were originally in Building 441. The Standards Laboratory, in Building 125, prepared 

analytical stock solutions for the other laboratories and performed analyses on incoming radiological 

sources for quality assurance/quality control purposes. In addition, the Standards Laboratory 

performed equipment calibration and standardization. The Plutonium Analytical Laboratory, in 

Building 559, conducted analyses to determine the purity of plutonium, concentrations of impurities, 

and makeup of plutonium alloys. The Building 881 Laboratories, also called the General Laboratories, 

opened in 1952 to perform wastewater, sludge, surface-water, and ground-water sample analyses. 

These laboratories analyzed production control samples from Buildings 460 and 444. When enriched 

uranium processes were in operation in Building 881, the laboratories also performed analyses of the 

products. 

The Filter Testing Group formed in 1979 after an audit identified the need for independent in-place 

leak testing of HEPA filters. In-place testing began in response to a filter change, when there was 

visible damage to the filter or the supporting framework, when plenum monitoring indicated a problem, 

and according to the routine testing schedule for that particular bank of filters. In addition, the Filter 

Testing Group conducted quality assurance testing on a fraction of new filters (preinstallation testing).

Laundry Services provided cleaning, sorting, and distribution of coveralls and other reusable garments 

required in the manufacturing areas. Available information does not indicate whether there were 

contamination concentration limits on laundry to be processed. Laundry water was sent to the forced 

evaporation operations in Building 374. Before Building 374 became operational in 1980, laundry 

water was sent to the second stage of Building 774 aqueous waste operations and then through the 

Building 774 evaporator if (presumably alpha-emitter) concentrations were above 1,667 pCi/L. Below 

this level, laundry water was sent to Pond B-2. In the very early days, Buildings 881, 771, and 991 

had their own laundry facilities, and Building 444 laundry went to Building 442. Around 1958, 

Building 778 became the laundry facility for all plutonium-handling buildings. When enriched uranium 

processing ended at Rocky Flats in 1964, laundry from Building 881 went to Building 778. Beginning 

in 1976, laundry from Building 444 DU operations was sent to Building 778 (ChemRisk 1992). 

Attachment B lists RFP job categories and descriptions. Attachment C is a partial list of types of 

radiation exposures associated with various job categories. This information is not presumed to be 

comprehensive, but was developed from several readily available documents.

2.3 RELEASES TO THE OUTDOOR ENVIRONMENT

2.3.1

ORAUT (2006c) contains details concerning stack and other effluent monitoring operations through 

the life of the facility. The RFP began onsite ambient air monitoring at a single station in 1952. By 

early 1953, 10 onsite stations had been established. The July 1953 monthly site survey report states 

that calibration and regulation of samplers to a flow rate of 2 cfm was under way. In February 1954, 

Whatman 41 filter paper was substituted for HV70 paper on all offsite samplers, because HV70 filters 

ruptured during the weeklong sampling. This implies that the use of HV70 filters continued for onsite 

(daily) sampling. In March 1956, manometers were installed on onsite units. In 1969, two more 

Airborne Emissions
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stations were added, for a total of 12 stations (ChemRisk 1992). Figure 2-5 shows key operations 

and notes plutonium air emissions associated with each facility during 1988. 

For a large part of the operational history of the Rocky Flats Plant, emissions were measured in terms 

of long-lived alpha radioactivity. This was true from 1953 to 1973 for plutonium and americium, and 

from 1953 to 1977 for uranium. From 1974 through 1984, 239/240Pu releases through routine 

operations were monitored by analytical techniques specific for the radionuclides. Americium-241 

was not included in the monitoring scheme. Between 1985 and 1989, 239/240Pu and 241Am were 

routinely sampled and monitored by alpha spectrometry following radiochemical separation but 241Pu 

was not included. Reporting of total long-lived alpha activity continued for uranium facilities until 

about 1977. Even after 1978, not all uranium isotopes were routinely analyzed. For example, only 

238U and 233/234U emissions were reported for 1978 to 1980 and 1984 to 1989. For 1981 to 1983, only 

total uranium emissions were reported. Beginning in 1974, annual airborne tritium release totals were 

reported in annual RFP environmental reports. In 1974, data were reported for 12 vents, which 

expanded to 18 in 1977 and 23 in 1981 (ChemRisk 1992). 

The largest routine releases of plutonium from RFP facilities occurred before 1975, primarily from the 

Building 771 stack and roof vents on Buildings 776 and 777. The largest routine plutonium releases 

from Building 771 occurred between 1957 and 1965; median release quantities after 1965 were below 

1,500 μCi. After 1970, median annual releases were below 500 μCi. Estimated total plutonium 

emissions, summed from the late 1950s to the mid-1960s, range between 1.3 and 6.5 mCi (Grogan et 

al. 1999).

2.3.2

There were two series of ponds at the site. The uncovered and unlined holding ponds were 

constructed on Woman Creek and on the north and south branches of Walnut Creek. The first three 

holding ponds were built in the early 1950s; eight more ponds were added over the years. The 

second series of ponds, called solar evaporation ponds, were built in the mid-1950s to enable the 

evaporation of liquids with low levels of radioactivity but high concentrations of nitrates.

Waterborne Emissions

Beginning in 1953, liquid effluent samples from RFP were collected and analyzed. The extent of the 

monitoring program, the spatial distribution of sampling, and the types of materials measured were 

limited until the early 1970s. Under the auspices of the Waste Disposal Unit, the Water Laboratory, 

which was part of the General Laboratory, conducted the analyses. The major focus of the analyses 

in the 1950s was on monitoring total solids and nitrates. With the exception of special circumstances, 

only gross alpha measurements were made before 1970. In general, there was no monitoring of 

plutonium, beryllium, or organic chemicals during this time, even though laundry wastes from 

Building 771 and effluents from the sanitary sewer system were discharged directly to Walnut Creek 

until 1974. As a result of the May 1969 fire, routine analyses of effluent and environmental water 

samples for plutonium began in September 1969. Plutonium and uranium were isolated from other 

long-lived alpha emitters by ion exchange, and their concentrations determined by alpha pulse-height 

spectrometry. Uranium recovery was determined by 232U tracers. 

2.4 ACCIDENTS

An extensive review of the Rocky Flats accident history occurred during Phases 1 and 2 of the 

environmental dose reconstruction. Researchers evaluated classified and unclassified accidentrelated databases and documents, resulting in the identification of thousands of small-scale releases 

and "accidents" over the 40-yr operating history. Many events reviewed during the investigation 

resulted in releases that passed through filtered building ventilation systems. The associated 
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Figure 2-5. Plutonium air emission sources in 1988. 
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releases were recorded as part of normal Plant operating emissions. Attachment D is a list of some 

accidents and incidents with potential for worker exposures; the list is not complete at this time, 

particularly for years after 1977. Details are being sought for several of the listed incidents and more 

current incidents are being researched. Not all of the accidents listed in Attachment D are known to 

have been associated with worker exposures; several are included only because they were likely to 

have involved significant disruptive mechanical force. 

Figure 2-6 shows gross alpha releases to the environment from 1953 to 1977. 

Figure 2-6. Reported gross alpha radioactivity emissions from Rocky Flats plutonium facilities. 

2.4.1

In 1958, site personnel developed a gamma spectrometer wound counter to confirm the presence of 

plutonium in wounds. In August 1961, 55 Alpha Flashers (later Alpha-Mets) were placed on 

gloveboxes in plutonium areas for workers to self-monitor their hands and identify a failed glove 

before spreading contamination. Introduction of “COMBOs,” combination hand and foot monitors, 

included floor areas in the contamination control program. Twenty continuous air monitors (CAMS) 

were in operation by April 1966 (locations unknown). Room air samplers were placed near exhaust 

ducts. Details concerning monitor types, introduction dates, minimum detectable activities, alarm 

characteristics, and related information are provided in ORAUT (2006b) where available. Additional 

study on the related topic of exposure of unmonitored workers proximate to Rocky Flats fires and 

Accidents and Contamination Control
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other accidents has been identified as an important issue for the Rocky Flats TBD team to undertake 

during follow-up work.

Following the two fires that caused major damage to production buildings in 1957 and 1969, there 

were changes to minimize the occurrence and consequences of fires. To reduce the probability of a 

fire, nitrogen atmospheres, minimal combustible loading in all areas, and improvement of fire 

detection and suppression systems were emphasized. The controlled use of automatic water fire 

suppression systems was included in the design of a new plutonium facility, Building 707, in 1967. 

Criticality concerns were addressed by enforcement of fissile limits and prevention of water 

accumulation. 

Figure 2-7 shows the locations of major accidents at the Rocky Flats Plant.

2.4.2

(NOTE: The information in this section is from ChemRisk 1992.) Fire was a continuous hazard when 

working with plutonium at the Plant. For example, RFP data indicate 623 reportable fires (most small) 

between January 1955 and December 1974. Of those fires, 387 occurred in plutonium processing 

areas. For perspective, records and interviews indicate that most fires were small and controlled, 

contained in glovebox or other airflow-controlled systems, and resulted in no inhalation exposure 

hazards to workers.

Accidents Involving Plutonium

The accident report on the 1969 fire states that 164 fires were reported to the Fire Department from 

1966 until the 1969 fire. Of these, 31 involved plutonium, of which 10 occurred in Buildings 776 and 

777. Of the remaining 133 fires, 17 occurred in Buildings 776 and 777. There is no reliable estimate 

of the number of plutonium fires not reported to the Fire Department. 

Chips from plutonium machining operations ignite easily if exposed to the air. Plutonium metal bums 

at a temperature near the 640°C melting point of plutonium, and there is no odor, smoke, or flames 

until other combustibles are involved. Small, relatively insignificant, plutonium fires were part of 

normal operations at RFP, and many such fires were not reported if they were confined in the 

production apparatus and there was no evident risk of human exposure. Emissions from most 

plutonium fires occurring during normal operations passed through multistage HEPA filter systems 

and contributed to normal operational releases of radionuclides. The 1957 fire was a significant 

exception.

The September 11, 1957, Fire

The September 11, 1957, fire (see Voillequé 1999a) began when metallic plutonium casting residues 

spontaneously ignited in a glovebox in Room 180 of Building 71 (later Building 771). The fire spread 

to an exhaust filter plenum, Rooms 281 and 282, consuming a considerable quantity of filters and 

damaging the ductwork and fan system. No major injuries were reported in this fire. 

Chronology of September 11 and 12, 1957:

10:10 p.m. Fire discovered in Room 180.

10:12 p.m. First fire truck arrived.

10:24 p.m. Carbon dioxide extinguishers first discharged at fire.

10:25 p.m. Fan system ordered on high speed.

10:37 p.m. Water spray nozzles discharged at fire.

10:38 p.m. Water shut off. Fire extinguished in Room 180.

10:39 p.m. Explosion in exhaust system; building evacuated due to contamination.
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Figure 2-7. Sites of the major accidents at the Rocky Flats Plant. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 28 of 80

10:40 p.m. Fans went off.

10:58 p.m. Second fire truck called.

11:10 p.m. Electrical power failed in entire building.

11:15 p.m. Water sprayed on filter bank.

2:00 a.m. Filter fire “knocked down.”

11:28 a.m. Final fire out.

Smoke from a burning glovebox, detected in a building hallway, led two watchmen to discover flames 

extending 18 in. from a Plexiglas window on a glovebox at approximately 10:10 p.m. on Wednesday, 

September 11, 1957. The fire started in a can of plutonium turnings in the “fabrication development 

line” in Room 180 (first floor) of the plutonium processing and fabrication building (Building 771). 

Because large quantities of plutonium were handled and stored in this area, people were delayed in 

fighting the fire until they could don adequate radioactive contamination protection. Attempts to fight 

the fire with carbon dioxide from hand extinguishers and a 100-lb cart were ineffective. A water spray 

nozzle was effective, although there was considerable uncertainty at the time about the potential for 

criticality. 

During this time, the fire spread to the filters, which introduced hot gases through the ventilation 

booster system and the main exhaust duct. Fires in the box exhaust booster filters and main filter 

plenum on the second floor might have started around this time, but were not discovered until 

10:28 p.m. An explosion of collected flammable vapors in the main exhaust duct at 10:39 p.m. 

resulted in spreading plutonium throughout most of the building. The Building 771 exhaust fans shut 

down at about 10:40 p.m. when power was lost. The only draft would have been that created by the 

natural updraft of the stack and through 100 ft or so of horizontal ductwork that leads to the base of 

the 150–175-ft stack. Supply fans might have created a positive pressure inside the building for about 

one-half hour. The fire in Room 180 was controlled at 10:38 p.m., but rekindled several times. The 

main filter fire was controlled at 2:00 a.m., and the fire was officially declared out at 11:30 a.m., 

Thursday, September 12, 1957. 

One of the two prefilter systems leading to the main plenum burned through during the 1957 fire. This 

was a two-stage prefilter system for laboratory gloveboxes and hoods and for the production 

development laboratory on the first floor. The exhaust filter plenum consisted of a long concreteblock-walled room into which individual exhaust systems discharged. The 620 Chemical Warfare 

Service 24-in.-square filters were held in a structural steel framework. 

Contamination and Dispersal of Soil from the Building 903 Drum Storage Area

In July 1958, an area just east of the main Plant site was designated a temporary storage area for 

contaminated oil drums. Many drums developed leaks due to stored chemical interactions, and 

plutonium-contaminated oil was deposited on the soil. Primarily between 1964 and 1969, the 

contaminated soil was suspended during windstorms (see Meyer at al. 1996; Weber et al. 1999). The 

area was later covered by an asphalt pad.

The following significant events were associated with the Plutonium-Contaminated Drum Storage 

(903) Area:

• July 1958–Drum storage area established. During subsequent years, drums that contained 

primarily plutonium-contaminated machining oils were continually added.

• July 1959–First drum leakage discovered. Rust inhibitor, ethanolamine, was added to drums 

prior to storage to minimize corrosion.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 29 of 80

• January 1964–First evidence of large-scale deterioration of drums reported. Soil 

contamination reported increasing.

• January 1966–Small building added to filter and transfer contaminated oil from leaking drums 

to new drums.

• January 1967–Last drums added to storage area; removal to Building 774 began. Oldest 

drums shipped first.

• June 1968–Last drum shipped to Building 774 for processing. High winds spread some 

contamination.

• July 1968–Radiation monitoring and mapping of area completed. Levels of 2 × 105 dpm/g of 

soil to more than 3 × 107 dpm/g were reported. Penetration from 1 in. to 8 in. was reported.

• September 1968–Preliminary proposal for containment cover prepared by RFP Facilities 

Engineering.

• July 1969–First coat of fill material applied.

• August 1969–Fill work completed, paving contract let.

• September 1969–Overlay material, soil sterilant, and asphalt prime coat completed.

• November 1969–Asphalt containment cover completed, including four sampling wells.

The first indication that drums were leaking in the field was in 1964. Contamination was detected on 

air samplers at the east fence following high winds. As a result, the storage area was fenced and 

contents of leaking drums were transferred to new drums. Approximately 420 drums leaked to some 

extent; of these, about 50 were totally empty. By the end of 1967, Plant officials discovered that soil 

contaminated by the leaking drums had been resuspended in the air and redeposited. 

The quantity redistributed was directly associated with the removal of the drums, which exposed 

contaminated soil, physical activity in the area, and the periodic high winds. In November 1968, 

grading began for applying an asphalt cap over the area. Most of the resuspension occurred between 

July 1968 and July 1969. The highest airborne concentration was 0.34 pCi/m3

, measured at a monitor 

approximately 100 m east of the 903 pad, in the prevailing wind direction. Installation of an asphalt 

pad began in July 1969 and ended in November 1969. A round of soil sampling in a 7-mi radius 

around the Plant was completed in late 1989. Plutonium concentrations were highest just east of the 

Plant (ChemRisk 1992). 

The May 11, 1969, Fire

A major plutonium fire started in a glovebox in the North Foundry Line in Building 776 on Sunday, 

May 11, 1969 (see Voillequé 1999b). The fire burned for several hours, spreading through 

combustible materials in several hundred interconnected gloveboxes in Buildings 776 and 777. The 

first indication of a fire was an alarm in the Fire Station in the North Foundry Line at 2:27 p.m. The 

Fire Department responded promptly, but on its arrival the fire was moving rapidly through the 

Foundry Conveyor Line. The fire spread through an interconnecting conveyor to the Center 

Fabrication Line. It was brought under control about 6:40 p.m., but continued to burn or reoccur in 

isolated areas through the night. On Monday morning, a fire discovered in a glovebox on the South 

Foundry Line, which was quickly extinguished, caused little damage.
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The dense smoke, crowded conditions, and presence of large quantities of combustible material in the 

form of Plexiglas windows and Benelex-Plexiglas shielding made the fire difficult to fight and 

extinguish. The fire did not breach the building roof, and ruptured only a minor part of one exhaust 

filter system. As a consequence, most of the smoke and essentially all of the plutonium remained in 

the building. One firefighter received a significant internal body burden of plutonium. There is no 

evidence that a criticality incident occurred. The damage to Buildings 776 and 777 and equipment 

was extensive. In addition to actual fire and smoke damage, the buildings were grossly contaminated 

with plutonium. Adjacent buildings sustained minor exterior and interior contamination. After the fire, 

processing and production gloveboxes at RFP were converted to an inert nitrogen atmosphere to 

prevent the spontaneous ignition of plutonium.

The first indication of a fire in Building 776 came from an alarm received in the Fire Station at 

2:27 p.m. The fire captain on duty and three firefighters responded to the initial alarm. They arrived 

at the west end of Building 776 at 2:29 p.m. On entering the building, they saw smoke coming toward 

them from the east. They proceeded farther into the building and observed heavy smoke and fire in 

the North Foundry Line. The fire was out of the top of the line with flames about 18 in. high. One of 

the firefighters heard two loud reports and saw two fireballs about basketball size go to the ceiling in 

the area of the North Foundry Line. This occurred while the firefighters were laying out a fire hose, 

and before any water had been used on the fire. By 2:50 p.m., there was fire along the top of the 

North-South Conveyor Line. About this time the firefighters on the second floor heard a loud noise 

and felt the floor shake. At approximately 3:20 p.m., the fire was spreading to the rolling mill on the 

Center Line, and at 3:40 p.m. the entire area from Columns G–J and 11–13 was glowing orange 

through dense smoke. There was also a fire in the ceiling in the vicinity of the North-South Conveyor 

Line.

Pressed plutonium briquettes composed of scrap metal and chips generated during rolling, forming, 

and machining operations self-ignited in metal storage containers in a Benelex and Plexiglas 

(transparent plastic materials) storage cabinet in the north line. Heat from the burning plutonium 

ignited the Benelex and Plexiglas in the glovebox line, which created large quantities of smoke. 

Visibility was nonexistent due to thick black smoke and the loss of lights in the main fire area. The 

crowded conditions in the fire areas made firefighting very difficult. The first attack on the fire with 

carbon dioxide was ineffective. Less than 10 min after the fire alarm was received, the fire captain 

initiated the use of water. Water was used on the fire almost exclusively, although some magnesium 

oxide was used on plutonium. 

Because the conveyor lines and gloveboxes were open, it was impossible to avoid getting water on 

the burning plutonium. As the glovebox windows burned, plutonium oxide was released to the room. 

Because of the extensive plutonium contamination and smoke, personnel entering the area during the 

fire were required to use self-contained breathing systems, which severely limited their time in the fire 

area. Attempts to pry or knock Benelex shielding from gloveboxes and conveyor lines were not 

successful. Although the firefighters were generally successful in knocking down the fire in some 

locations, by the time they returned with new air supplies or from directing their attention to other 

areas, the fire was again intense. 

Some smoke came out the west end doors of Building 776, which were opened at about 2:29 p.m. 

Between 3:20 p.m. and 4:10 p.m., smoke was observed coming from the roof of Building 776. The 

smoke billowed over the side of the building toward Buildings 778 and 750. Firefighters sent to the 

roof saw smoke coming from exhaust vents. Although there were no signs of fire in the roof, the roof 

did soften in one area near the location of the 4 High Mill, Columns H–G and 6–7. The roof was 

sprayed with water and a fire watch maintained until after 5:00 p.m. By 6:40 p.m., the fire was 

contained. Between 7:00 p.m. and 8:00 p.m., a door on the second floor of Building 776 was opened 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 31 of 80

and the main building exhaust system was changed from recirculating to single-pass in an effort to 

help clear the heat and smoke. By 8:00 p.m., the fire was largely extinguished, and a fire watch was 

established. During the early morning hours of Monday, May 12, the storage container in Glovebox 

134-24 on the North Foundry Line continued to smolder and reignite. Water and magnesium oxide 

were used on this container. Between 8:00 a.m. and 9:00 a.m. on Monday, the fire watch discovered 

a fire in the plutonium storage box on the South Foundry Line (Glovebox 134-70). This fire was 

quickly extinguished by breaking the Plexiglas windows and using water on both the inside and 

outside of the box. This was the only fire in the South Foundry Line.

The fire destroyed the gamma radiation alarm system in Building 776, but the Building 777 alarm 

system remained operational. Neither this system nor those in Buildings 559, 779, and other 

locations on the Plant were set off during or after the fire. A Hurst dosimeter retrieved from 

Building 776 showed no evidence of being exposed to neutrons or gamma radiation. No one reported 

seeing a visible flash or any other sensory evidence that a nuclear criticality had taken place.

One area of the roof of Buildings 776 and 777 near the exhaust vent from Booster System No. 1 was 

contaminated with plutonium in the range of 105

 – 106 cpm, which corresponded to 0.2 μCi/100 cm2. 

Adjoining ground areas and the exterior of Building 777 were contaminated on the order of 105

 – 

106 cpm. The ventilating, electrical, and other utility systems on the second floor of Building 776 were 

similarly contaminated with plutonium. Approximately 8 mCi of plutonium appears to have escaped 

from Buildings 776 and 777 and deposited on the roof or adjoining soil (Voillequé 1999b). It was 

primarily deposited on the roof of the building and on the ground and one building adjacent to 

Buildings 776 and 777 (ChemRisk 1992). 

The 1965 Glovebox Drain Fire

In 1965, a plutonium fire occurred during a maintenance operation on a plugged glovebox drain in 

Buildings 776 and 777 (see Voillequé 1999c). The fire vented to the room air and spread throughout 

the buildings through the normal ventilation system. About 400 employees, many without respirators, 

were potentially exposed to airborne plutonium dioxide. Body counter measurements indicated that 

25 employees received 1 to 17 times the permissible lung burden. Lung concentrations greater than 

0.008 μCi were found in 15 employees.

At approximately 10:25 a.m. on Friday, October 15, 1965, a fire occurred during a lathe maintenance 

operation in Room 130 of Building 777. The operation involved unplugging a coolant recirculation line 

for a tape-controlled turning machine. Attempts to remove the obstruction from the glovebox end of 

the line failed; attempts were made to unplug the line through a drain leg near the glovebox. A cap 

was removed from the bottom end of the drain leg and a center punch was inserted to dislodge the 

obstruction. Sparking was observed when the punch was struck, and a fire resulted, burning the bag 

enclosure for the punch and igniting a plastic and paper pen directly beneath the drain leg.

The fire lasted for one-half to 1-and-a-half minutes and was extinguished with carbon dioxide. It 

vented to the room atmosphere and combustion products were widely spread by the normal 

ventilation pattern. Residues of the fire and a drain leg removed from an adjacent lathe were 

analyzed. The analyses indicated that, during the fire, a chemical reaction occurred between 

plutonium and carbon tetrachloride. The burning of plutonium in air is generally nonviolent and 

described as smoldering. The reaction of plutonium and carbon tetrachloride can be violent.

Fifteen employees had greater than 0.008 μCi of plutonium in their chest counts. Plutonium 

contamination was spread through a major portion of Building 776 and through 25,000 ft2 of 

Building 777. Major areas of the buildings were cleaned up by Monday morning, October 18, and 

nearly all production operations resumed at that time (ChemRisk 1992).
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 32 of 80

The 1974 Control Valve Release

Radioactive particulates escaped from an exhaust stack on the roof of Building 707-A following a 

glovebox atmosphere control valve accident at about 9:53 a.m. on April 2, 1974 (see ChemRisk 

1992). At approximately 1 p.m., Wednesday, April 3, 1974, an elevated count was detected on the 

exhaust stack sample of Inert System No. 2 and Downdraft Plenum No. 4. Results of surveys showed 

the path of contamination movement in the inert system. A flow reversal had apparently occurred 

through the recirculating fans resulting in a release to the environment. 

The accident resulted when the inert atmosphere exhaust valve from the Building 707 storage vault 

was being closed during a glovebox maintenance procedure. This resulted in a pressure surge that 

forced contaminated gas back upstream through the inert gas supply system. The contaminated gas 

was pumped into the atmosphere by the purge exhaust fans through the exhaust stack shared by 

Inert System 2 and Downdraft Plenum 4. This transport of contaminated gas in turn contaminated the 

exhaust ducts. In addition, the pressure surge caused contaminated gas to flow out the open window 

of glovebox 7-K-65, which had been removed for maintenance. This contaminated a nearby module 

to levels up to 100,000 cpm, and tripped the air monitors. 

Table 2-1 summarizes releases to the environment for several Rocky Flats facility events.

Table 2-1. Plutonium release estimate distributions by event.

a

Release event

Distribution of estimated release quantity (Ci)

5th percentile 50th percentile 95th percentile

1957 fire 11 21 36

1969 fire 0.013 0.037 0.062

903 Areab 1.4 3.1 15

a. Modified from Grogan et al. (1999).

b. Releases to air, primarily 1964–1969. Includes particles up to 30 μm 

aerodynamic equivalent diameter (AED); ~20% were estimated to be in the 

respirable size fraction (<15 μm AED). ORAUT (2006b) considers particle 

size conventions and methods to convert from one system to another. Work 

remains to be done in this area for the Rocky Flats Site Profile, and this has 

been noted in ORAUT (2006b).

2.4.3

Tritium has been present at Rocky Flats since 1964 as transshipments, for “special order” work, as 

standards, in contaminated materials, and as nondestructive testing sources (ChemRisk 1992). Two 

measurable releases of tritium occurred at the Rocky Flats Plant (ChemRisk 1992, 1994a, 1995). An 

accident in 1968 led to the release of several hundred curies and another in 1973 released 500 to 

2,000 Ci. The 1973 release occurred when tritium-contaminated-material was inadvertently 

processed. An estimated 60 Ci of tritium was released in water effluents, 100 to 500 Ci was retained 

in onsite ponds and tanks, and the remainder escaped to the atmosphere. There were five known 

sources of tritium effluent releases at RFP: Building 779; Building 561; Building 777, which released 

tritium in the 1973 incident; Building 774, where tritium-contaminated water was evaporated; and the 

four solar evaporation ponds adjacent to Building 779. The solar ponds were the source of water fed 

to the Building 774 evaporator (ChemRisk 1992). In addition, approximately 1.5 Ci of tritium was 

released in Room 452 of Building 777 in 1974. Figure 2-8 illustrates tritium operations locations.

Tritium at Rocky Flats

2.4.4

Based on information gathered during an extensive investigation of accident records during the 

Phase 1 and 2 environmental dose reconstruction project, it is believed that incidents involving 

uranium at RFP have been relatively rare. One exception was associated with the practice of onsite 

Accidents Involving Uranium
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 33 of 80

Figure 2-8. Tritium air emission sources. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 34 of 80

burning of wood pallets. In May 1965, three DU sheets were accidentally burned as a result of 

shipment to RFP from Medina, Ohio, in a package that resembled a nonstandard-size wooden pallet. 

Improper labeling and the unconventional packaging apparently caused the DU to go undetected, and 

the pallet containing 60 kg of slightly radioactive DU was destroyed by burning on May 1, 1965.

Figure 2-9 illustrates the locations of uranium operations on the site.

2.4.5

Attachment D contains information from a variety of reports. Incidents reported after 1981 were 

compiled in occurrence reports (RFETS 1981–2005) by RFP management. Over 10,000 pages of 

reports have been located at the Rocky Flats Reading Room in Westminster, Colorado. Certain 

incidents involving radiation exposure to workers that required submittal of bioassay samples, 

relatively significant exposure, or involving more than one employee have been included in 

Attachment D. The list should not be considered comprehensive for the following reasons: 

Accidents and Occurrences after 1981

1. Many occurrence reports, numbered sequentially for each building and year, were found to be 

missing from the available collection at the Rocky Flats Reading Room, the only known 

repository at this time. Some of the reports might have been reserved for security reasons or 

because they contained classified information. Others are missing all but the first page, which 

does not provide sufficient detail to determine whether an exposure occurred. Note that the 

reports do not contain information that would identify the individual(s) involved. Only the 

supervisor/report authors are identified in the incident reports.

2. It is not known whether all incidents of potential interest to dose reconstruction are captured in 

the reports. All available records were searched but it is possible that other incident reports 

are located elsewhere. Also, reports from the 1980s appeared to capture only occurrences 

that could have resulted in employee exposure to radiation, but reports from the 1990s 

captured any off-normal occurrence, from accidental radiation exposure and replacement of 

worn or defective equipment to employee disputes and procedural violations that did not 

involve any radiation exposure. Given the different reporting requirements through the years, 

a different number of reportable events are documented.

3. There was a lag time between incident reporting (usually done quickly) and reporting of 

bioassay results (due to processing). It is possible that an exposure was not captured in an 

occurrence report because bioassay results were not provided in the incident report or in a 

follow-on report.

In addition to the occurrence reports, two other sources were searched for incidents of potential 

interest; the Price-Anderson Enforcement Actions (www.eh.doe.gov/enforce/eas.html) and the 

Kaiser-Hill quarterly reports [Total Project Summary (TPS) Reports] of remediation progress available 

from the fourth quarter of fiscal year (FY) 2001 to the first quarter of FY 2005 (www.rfets.gov; RFETS 

2006a). The TPS Reports are not available before July 2001 because they were not produced, and 

there appears to be no comparable report of remediation incidents for prior dates. 

The TPS reports (RFETS 2006a) contained detailed safety analyses starting in the third quarter of 

2003 (April-June 2003). Prior to that time, only the number of incidents involving radiation were 

reported. Table 2-2 lists results for those years.

Starting in the third quarter of FY 2003 (April–June 2003), “serious” incidents and skin contamination 

were reported in detail. The total number of incidents involving radiation is not reported. There is no 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 35 of 80

Figure 2-9. Uranium air emissions sources. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 36 of 80

Table 2-2. Incidents involving radiation. 

Date Number of Incidents

July–September 2001 142

October–December 2001 134

January–March 2002 187

April–June 2002 327

July–September 2002 No report found

October–December 2002 85

January–March 2003 261

overlap with the occurrence reports, which apparently stopped in 2002. Incidents detailed in the TPS 

reports (RFETS 2006a) are shown in Attachment D, Table D-3. Skin contamination events are 

reported only if the contamination was greater than 1,000 dpm/100 cm2 or was part of the “serious” 

incidents noted in the TPS report.

The Price-Anderson Enforcement Actions overlap in time with the occurrence reports. However, three 

enforcement actions that did not appear to have concurrent occurrence reports are noted here. The 

enforcement action notices withhold certain information, like building numbers and dose received, that 

will make use of this information difficult for the dose reconstructors; however, for completion, the 

incidents are reported below: 

• Enforcement Action 98-03: (1) Unplanned uptake of radioactive material by two workers

during a Comprehensive Environmental Response, Compensation, and Liability Act tank 

remediation project of August 12, 1996, conducted by Rocky Mountain Remediation Service 

(RMRS); (2) 17 workers receiving small radiation exposures (6 in 1996 and 11 in 1997) as a 

result of inadequate assessment of area dosimetry data for several offices adjacent to rooms 

containing radioactive material; and (3) an RMRS sealed-source custodian receiving 

unnecessary exposure while performing a radioactive source inventory and leak test on 

January 14, 1998.

• Enforcement Actions 97-03 and 97-04: Unplanned dispersal of radioactive material during 

remediation of trenches (September 19, 1996). The radioactive material was dispersed when 

a radioactively contaminated drum carcass was compacted by a backhoe in support of trench 

remediation being performed by RMRS. Approximately 1 to 2 lb of an unnamed radioactive 

material was released. The release was identified several hours later and the release area 

secured, “A subsequent dose determination using air dispersion modeling and conservative 

assumptions estimated that onsite and offsite doses were minor.” 

• Enforcement Actions 96-04 and 96-05: Two incidents involving radiological exposure to 

workers. On March 4, 1996, a release of radiation in excess of unnamed limits occurred, and 

work was not stopped even though the work permit required it. Two workers and others 

nearby continued to work in increasingly hazardous conditions. Similar violations occurred on 

April 18, 1996, in another building. Five workers received varying levels of unexpected 

radiation contamination while performing bag-out activities. Workers were not wearing 

required respiratory protection at the time. 

2.5 SITE CLOSURE AND DECOMMISSIONING

In December 1988, an aircraft on a routine operation equipped with an infrared camera recorded a 

heat plume from the Building 771 Incinerator. U.S. Environmental Protection Agency (EPA) officials 

believed that illegal incinerator operations were being conducted, and on June 6, 1989, the Federal 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 37 of 80

Bureau of Investigation raided Rocky Flats based on the allegations of Resource Conservation and 

Recovery Act and Clean Water Act violations. Although the allegations could not be confirmed, other 

safety concerns led to curtailment of operations in 1989 (KHC 2004a). Cleanup of the site started in 

December 1995 following a grand jury hearing in 1992. For additional information concerning site 

remedial action, see also “Historical American Engineering Record at Rocky Flats Environmental 

Technology Site” (RFETS 2006b). 

The Rocky Flats Cleanup Agreement (RFCA) between DOE, EPA, and the Colorado Department of 

Public Health and Environment was finalized July 19, 1996. The RFCA set out a timeline and goals 

for site remediation, and included demolition of buildings that could not be safely remediated and 

reused. The agreement specified that remediation of chemical and radioactive waste, buildings, 

equipment, soil, ground water, and surface water would need to be accomplished with the goal of 

returning the site to a wildlife preserve (www.rfets.gov). Attachments to this agreement with specific 

remediation goals were finalized in June 2003 (KHC 2003a).

Closure of the Rocky Flats Environmental Technology Site (RFETS), as it was called during the 

remediation and decommissioning process, was a complicated matter due to the presence of TRU 

waste, TRU mixed waste, low-level radioactive waste, low-level mixed waste, sanitary waste, and 

chemical waste. “Orphaned” waste was also present on the site and had been stored there lacking a 

final disposal site. In addition, decontamination of buildings and equipment was necessary before 

buildings could be demolished. Soil and water also required remediation and restoration. Highlights 

of the decommissioning projects, which included demolition of all buildings on RFETS, are described 

below (KHC 2003a-2003p, 2004a-2004n, and 2005a-2005g). Only two major incidents were reflected 

in the 2-and-a-half years of reports found: one is described in Section 2.7.1 and included in Table C-3 

of Attachment C; the other is described in Section 2.7.8 and did not involve radiation.

In general, the buildings were subdivided into groups for the purposes of remediation and 

decontamination and decommissioning (D&D), in general conforming to their uses during the 

production years. The building clusters were further subdivided into dismantlement sets (or Sets) 

based on similarity of remediation work to be performed, and decommissioning areas, referring to 

demolition proceedings. Buildings and areas were ranked by level of contamination. Type 1 denoted 

being free of contamination, Type 3 denoted high levels of contamination or hazard. Type 2 denoted 

the need for remediation but without significant hazard or contamination (DOE 1999).

2.5.1

The Building 371/374 Closure Project was comprised of Buildings 371, 374, 373, 374A, 377, 378, and 

381, and 14 aboveground storage tanks, located within the Protected Area. All were slated for 

demolition to be consistent with the goal of permanent closure of RFP. The closure project had to 

deal with both radiological and chemical cleanup of the buildings, but only Buildings 371 and 374 were 

classified as highly contaminated (DOE 2001). 

Building 371

All special nuclear material (SNM) was removed from Building 371 Central Storage Vault on 

December 30, 2002. All plutonium oxide was removed from Building 371 and sent to the Savannah 

River Site, and the International Atomic Energy Agency closed building surveillance in December 

2002 (KHC 2003b). On May 6, 2003, a fire occurred in glovebox 8 of Building 371 (KHC 2003c); this 

incident, which resulted in a Price-Anderson Enforcement Action Investigation, is included in 

Table D-2 of Attachment D. Rasching ring removal was completed on June 16, 2003 (KHC 2003d). 

On August 8, 2003, the Building 371 Material Access Area was closed, paving the way for the 

elimination of the Protected Area (KHC 2003e); the Protected Area was eliminated by November 2003 

(KHC 2003f). 
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Also by November 2003, all weapons-usable material from Building 371 had been shipped from the 

site and removal of more than 36,000 gal of sludge from 28 tanks was completed (KHC 2003f). 

Remaining sludge was removed from Buildings 371/374 by February 2004 (KHC 2004b) and the 

buildings were declared criticality incredible by August 2004 (KHC 2004c). All TRU equipment had 

been removed from Building 374 by August 2004. Remaining plutonium stabilization and packaging 

system Plutonium Stabilization and Packing System equipment was removed from Building 371 on 

July 21, 2004 (KHC 2004c). 

The last glovebox was removed from Building 371 on November 22, 2004, and the last TRU waste 

from the building was shipped on November 17, 2004 (KHC 2004d). By mid-December 2004, the 

Central Vault had been size-reduced and partially removed (KHC 2004e). D&D continued in January 

2005 (KHC 2005a) and the last phase of Building 371 demolition began in June 2005 (KHC 2005b). It 

was completed by September 2005 (KHC 2005c).

2.5.2

The beryllium plenum of Building 444 was removed by December 2003 (KHC 2003g). Demolition of 

the Building 444 structure was completed by April 2005 (KHC 2005d). Decommissioning posed 

significant challenges due to the extent of beryllium contamination (KHC 2005d) but no details of any 

radiation issues have been found to date. 

Building 444

2.5.3

The Decommissioning Operations Plan (DOE 2000) states that the Building 707 Closure Project was 

comprised of Buildings 707, T-707S, 708, 709, 711, 711A, 718, 731, 732, and 778, and 21 

aboveground storage tanks located within the Protected Area. Some areas within the Building 707 

Project had levels of radiological contamination exceeding 2,000 dpm/cm2 removable and 

50,000 dpm/100 cm2 fixed plus removable. All facilities within the Building 707 Cluster were slated for 

demolition (DOE 2000). 

Building 707 Closure Project

The remediation of the C-pit of Building 707 was completed by January 2003 (KHC 2003h). By 

September 5, 2003, the X-Y retriever was emptied of all contents and part holders (KHC 2003i). The 

J-module was dismantled in early 2004 (KHC 2004f) and criticality incredibility was achieved in the 

facility in March 2004 (KHC 2005a). The X-Y retriever vault was decontaminated and removed by 

November 2004 (KHC 2004g).

Decontamination of Building 707 was accomplished using dry techniques (concrete shavings). 

Decontamination and final surveys of 228,000 ft2 were finalized (KHC 2005a) and Building 707 was 

demolished on December 7, 2004 (KHC 2004e). By the time the demolition was complete, no 

criticality infractions or deficiencies had occurred in the past 20 mo and no recordable injuries had 

occurred in the past 9 mo (KHC 2005a). 

2.5.4

The original Decommissioning Operating Plan for Building 771 was approved in January 1999; 

modification 5 dated August 8, 2003 (DOE 2003), is referenced here. The 771 Closure Project 

included Buildings 771 and 774. Facilities within the 771 Closure Project were slated for D&D. Thirtythree dismantlement sets and 13 decommissioning areas were defined for this project and, as of 

August 8, 2003, most of the sets and some of the areas had been dispositioned (DOE 2003).

771 Closure Project
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 39 of 80

Through FY 2003, all 240 gloveboxes and 397 tanks from Buildings 771 and 774 were removed and 

both buildings were declared criticality incredible. Plenums FU-2B and FU-2C were dismantled and 

removed. The main filter plenum was decommissioned. Two of the 13 decommissioning areas were 

surveyed and certified for demolition. The maintenance shop, tank shed, guard shack, and trailers 

were demolished. Removal of two underground storage tanks had begun (KHC 2003f).

Building 774, the “infinity room,” and the Building 771 stack were demolished in June 2004 (KHC 

2004h). The infinity room was so named because the measured derived air concentrations (DACs) 

were greater than 2,000 times the maximum limit for safe entry 25 yr after it had been sealed and 

abandoned due to contamination (KHC 2004a). Building 771 demolition began in July 2004 and 

ended October 12, 2004 (KHC 2004g). 

2.5.5

The Building 776/777 cluster was comprised of Buildings 701, 702, 703, 710, 712, 712A, 713, 713A, 

730, 776, 777, and 781. Decommissioning (including demolition) was chosen as the best alternative 

for this cluster to support the goal of a safe, accelerated, cost-effective closure (DOE 1999). The 

buildings were classified as to level of contamination and remediation began. 

Building 776/777 Cluster

By January 2003, Building 776/777 was declared criticality incredible. By the end of FY 2003, 

decontamination and decommissioning of all buried equipment was completed. Building 776/777 

went “cold and dark” by October 2003, meaning all radioactive material and permanent power sources 

were removed. By November 2003, Plenums 204, 205, and 206 had been removed, and 

decontamination of the Advanced Size Reduction Facility (ASRF) was completed. Workers made 

more than 900 entries in supplied air breathing suits while demolishing and removing the facilities 

(KHC 2003f). All major equipment and gloveboxes were removed by the end of 2003 (KHC 2004a).

Piping, conduit, and ducts were removed in 2004 and all 10 support buildings were demolished (KHC 

2005a). Strip-out of all equipment was completed in 2004, and encapsulation of floor space began in 

preparation for controlled demolition (KHC 2005a). As of the end of 2004, no Technical Safety 

Requirements (TSR) violations had occurred for 42 mos, no criticality infractions or deficiencies had 

occurred for 19 mo, and no recordables had occurred for the past 15 mo (KHC 2005a). Demolition of 

Building 776/777 began in January 2005 and was complete by June 2005 (KHC 2005c).

2.5.6

Few details on the D&D of Building 881 have been found. However, D&D began in January 2003 

(KHC 2004a). Strip-out operations had removed 460 tons of low-level and low-level-mixed wastes by 

June 2003 (KHC 2003j). The Building 881 ventilation stack was removed on November 8, 2003 (KHC 

2003k). Final demolition was on July 17, 2004 (KHC 2004a). 

Building 881

2.5.7

Drums stored at the 903 Pad had leaked 5,000 gal of plutonium-contaminated liquid between 1958 

and 1967. The 903 Pad was removed, and excavation was a 13-mo project that was completed by 

December 2003. More than 32,000 tons of plutonium-contaminated soil and asphalt were removed 

from the pad area during that period. It was one of the largest and most visible environmental 

restoration projects at Rocky Flats (KHC 2003g).

903 Pad and Lip

D&D continued on the 903 Pad Lip Area (36 acres east of the pad that had been affected by winddispersed contamination) and was completed by September 2004 (KHC 2004i).
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 40 of 80

2.5.8

The west tunnels and three vaults were closed on April 23, 2003 (KHC 2003l), but a fire had occurred 

in one tunnel during closure on February 12, 2003. The cause was determined to be smoldering foam 

(foam had been used to permanently fill and seal the tunnels) (KHC 2004f). No personnel exposure 

to radiation resulted from this incident because no radioactive material was present in that area (KHC 

2004f).

Building 991

The last TRU waste shipment from Building 991 was on September 12, 2003 (KHC 2003m). 

Remaining tunnels were closed and full-scale demolition of Building 991 began on March 9, 2004 

(KHC 2004f). By March 24, 2004, essentially all of Building 991 had been demolished (KHC 2004j).

2.5.9

The following information was located for buildings that did not fall into the major D&D groups. All 

details found have been provided in chronological order.

Other Buildings

• Building 779 was demolished in January 2000 (KHC 2003f).

• Remediation of the Solar Ponds was completed in January 2003 (KHC 2003b). The ponds 

were emptied and soil, building slabs, supporting equipment, and pumps were removed. 

Clean soil was used as backfill for the ponds. Top soil was added and the area reseeded in 

March 2003 (KHC 2003b). 

• The following structures were demolished as of March 12, 2003 (KHC 2003n): Building 112, 

T441A, T121A, T886D, Building 992, Building 449, Building 449A, Building 449C, shed 449, 

Building 427, Building 427A, Building 453, and the paint shed of Building 444.

• The 280 landfill was closed by January 29, 2003 (KHC 2003o).

• Building 441 was demolished on March 13, 2003 (KHC 2003p).

• Building 443 was demolished on June 14, 2004 (KHC 2004h).

• The following structures were demolished as of October 1, 2003 (KHC 2003i): 790, 112, 441, 

334, 55, 552, 865, PACs 2, valve vaults of Building 428.

• The Water Tower was removed on November 8, 2003 (KHC 2003k).

• Three guard towers were removed in 2002, and the last one in November 2003 (KHC 2003k). 

• Building 779 was demolished as of March 2004 but the exact date is unclear (KHC 2004k).

• Buildings 130 and 131 were demolished in March and April of 2004 (KHC 2004l). These 

buildings housed offices, administrative functions, and a kitchen.

• The nitrogen plant, Building 223, was demolished on May 11, 2004 (KHC 2004h).

• Additional FY 2004 demolitions were Buildings 116, 119, 128, and 443, and Trailers T119B 

and T117A.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 41 of 80

• The last TRU waste shipment from Building 664 left the site on July 30, 2004 (KHC 2004c). 

Building 664 was demolished on November 6, 2004 (KHC 2004d).

• Building 750 (the cafeteria) was demolished on August 10, 2004 (KHC 2004m).

• Demolition of Buildings 121 and 122 started on September 13, 2004, and ended within days 

(KHC 2004i).

• The Firing Range was demolished on October 12, 2004 (KHC 2004n).

• The Building 447 Foundry was demolished by November 2004 (KHC 2004n).

• Building 331 (Fire Department) closed on July 1, 2005 (KHC 2005e) and was demolished in 

late July (KHC 2005f).

• The last buildings on the site were T130H (demolished September 9, 2005) and T130 

(demolished September 8, 2005) (KHC 2005g).

2.6 ATTRIBUTIONS AND ANNOTATIONS

None.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 42 of 80

REFERENCES

AEC (U.S. Atomic Energy Commission), 1975, Operational Accidents and Radiation Exposure 

Experience Within the United States Atomic Energy Commission, 1943-1970, WASH-1192-

REV, Washington, D.C.

ChemRisk, 1992, Reconstruction of Historical Rocky Flats Operations and Identification of Release 

Points, Project Task 3 & 4 for Phase I, Final Draft Report, Alameda, California, August. 

ChemRisk, 1994a, Estimating Historical Emissions from Rocky Flats 1952-1989, Project Task 5 for 

Phase I, Alameda, California, March. 

ChemRisk, 1994b, Dose Assessment for Historical Contaminant Releases from Rocky Flats, Project 

Task 8 for Phase I, Alameda, California, September.

ChemRisk, 1995, Dose Assessment for Historical Contaminant Releases from Rocky Flats, Project 

Task 8 for Phase I, Alameda, California, January.

DOE (U.S. Department of Energy), 1980, Final Environmental Impact Statement, Rocky Flats Plant, 

DOE/EIS-0064, Golden, Colorado, April.

DOE (U.S. Department of Energy), 1999, Building 776/777 Closure Project Decommissioning 

Operations Plan, Revision 0, Rocky Flats Environmental Technology Site, Golden, Colorado, 

November 3.

DOE (U.S. Department of Energy), 2000, Building 707 Closure Project Decommissioning Operations 

Plan, Rev. 0, Rocky Flats Environmental Technology Site, Golden, Colorado.

DOE (U.S. Department of Energy), 2001, Building 371/374 Closure Project Decommissioning 

Operations Plan, Rev. 0, Rocky Flats Environmental Technology Site, Golden, Colorado.

DOE (U.S. Department of Energy), 2003, 771 Closure Project Decommissioning Operations Plan, 

Modification 5, Rocky Flats Environmental Technology Site, Golden, Colorado.

Grogan, H. A., P. D. McGavran, K. R. Meyer, H. R. Meyer, J. Mohler, A. S. Rood, W. K. Sinclair, P. G. 

Voillequé, J. M. Weber, J. E. Till, 1999, Technical Summary Report for the Historical Public 

Exposures Studies for Rocky Flats Phase II, FINAL, Radiological Assessments Corporation, 

Neeses, South Carolina, September.

KHC (Kaiser-Hill Company), 2003a, endvision, volume 9, number 12, Broomfield, Colorado, June 18.

KHC (Kaiser-Hill Company), 2003b, endvision, volume 9, number 2, Broomfield, Colorado, 

January 29.

KHC (Kaiser-Hill Company), 2003c, endvision, volume 9, number 17, Broomfield, Colorado, 

September 3. 

KHC (Kaiser-Hill Company), 2003d, endvision, volume 9, number 13, Broomfield, Colorado, July 2. 

KHC (Kaiser-Hill Company), 2003e, endvision, volume 9, number 16, Broomfield, Colorado, 

August 19. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 43 of 80

KHC (Kaiser-Hill Company), 2003f, endvision, volume 9, number 21, Broomfield, Colorado, 

November 14. 

KHC (Kaiser-Hill Company), 2003g, endvision, volume 9, number 23, Broomfield, Colorado, 

December 17.

KHC (Kaiser-Hill Company), 2003h, endvision, volume 9, number 2r, Broomfield, Colorado, 

January 29.

KHC (Kaiser-Hill Company), 2003i, endvision, volume 9, number 19, Broomfield, Colorado, October 1. 

KHC (Kaiser-Hill Company), 2003j, endvision, volume 9, number 11, Broomfield, Colorado, June 4. 

KHC (Kaiser-Hill Company), 2003k, endvision, volume 9, number 22, Broomfield, Colorado, 

November 25. 

KHC (Kaiser-Hill Company), 2003l, endvision, volume 9, number 8, Broomfield, Colorado, April 23. 

KHC (Kaiser-Hill Company), 2003m, endvision, volume 9, number 20, Broomfield, Colorado, 

October 22. 

KHC (Kaiser-Hill Company), 2003n, endvision, volume 9, number 5, Broomfield, Colorado, March 12. 

KHC (Kaiser-Hill Company), 2003o, endvision, volume 9, number 1, Broomfield, Colorado, January 8.

KHC (Kaiser-Hill Company), 2003p, endvision, volume 9, number 6, Broomfield, Colorado, March 26.

KHC (Kaiser-Hill Company), 2004a, endvision, volume 10, number 11, Broomfield, Colorado, July 26. 

KHC (Kaiser-Hill Company), 2004b, endvision, volume 10, number 3, Broomfield, Colorado, 

February 19. 

KHC (Kaiser-Hill Company), 2004c, endvision, volume 10, number 12, Broomfield, Colorado, 

August 12.

KHC (Kaiser-Hill Company), 2004d, endvision, volume 10, number 17, Broomfield, Colorado, 

December 1.

KHC (Kaiser-Hill Company), 2004e, endvision, volume 10, number 18, Broomfield, Colorado, 

December 15. 

KHC (Kaiser-Hill Company), 2004f, endvision, volume 10, number 5, Broomfield, Colorado, March 16. 

KHC (Kaiser-Hill Company), 2004g, endvision, volume 10, number 15, Broomfield, Colorado, 

October 20.

KHC (Kaiser-Hill Company), 2004h, endvision, volume 10, number 9, Broomfield, Colorado, June 23.

KHC (Kaiser-Hill Company), 2004i, endvision, volume 10, number 14, Broomfield, Colorado, 

September 30. 

KHC (Kaiser-Hill Company), 2004j, endvision, volume 10, number 6, Broomfield, Colorado, March 24. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 44 of 80

KHC (Kaiser-Hill Company), 2004k, endvision, volume 10, number 4, Broomfield, Colorado, March 3.

KHC (Kaiser-Hill Company), 2004l, endvision, volume 10, number 7, Broomfield, Colorado, May 10. 

KHC (Kaiser-Hill Company), 2004m, endvision, volume 10, number 13, Broomfield, Colorado, 

September 7.

KHC (Kaiser-Hill Company), 2004n, endvision, volume 10, number 16, Broomfield, Colorado, 

November 3.

KHC (Kaiser-Hill Company), 2005a, endvision, volume 11, number 1, Broomfield, Colorado, 

January 19.

KHC (Kaiser-Hill Company), 2005b, endvision, volume 11, number 3, Broomfield, Colorado, May 11.

KHC (Kaiser-Hill Company), 2005c, endvision, volume 11, unnumbered, Broomfield, Colorado, 

June 15.

KHC (Kaiser-Hill Company), 2005d, endvision, volume 11, number 2, Broomfield, Colorado, April 18. 

KHC (Kaiser-Hill Company), 2005e, endvision, volume 11, number 5, Broomfield, Colorado, June 30.

KHC (Kaiser-Hill Company), 2005f, endvision, volume 11, number 6, Broomfield, Colorado, 

August 10.

KHC (Kaiser-Hill Company), 2005g, endvision, volume 11, number 7, Broomfield, Colorado, 

September 19.

McLaughlin, T. P., S. P. Monahan, and N. L. Pruvost, 2000, A Review of Criticality Accidents, 

LA-13638, Los Alamos National Laboratory, Los Alamos, New Mexico, May.

Meyer, K. R., and J. E. Till, 1999, Characterization of Releases to Surface Water from the Rocky Flats 

Plant, RAC Report 7-CDPHE-1996-FINAL (Rev. 1), Radiological Assessments Corporation, 

Neeses, South Carolina, August.

Meyer, H. R., S. K. Rope, T. F. Winsor, P. G. Voillequé, K. M. Meyer, L. A. Stetar, J. E. Till, and J. M. 

Weber, 1996, Task 2: The Rocky Flats Plant 903 Area Characterization, RAC Report 2-

CDPHE-RFP-1996-FINAL, Radiological Assessments Corporation, Neeses, South Carolina. 

NIOSH (National Institute for Occupational Safety and Health), 2002a, External Dose Reconstruction 

Implementation Guideline, OCAS-IG-001, Office of Compensation Analysis and Support, 

Cincinnati, Ohio.

NIOSH (National Institute for Occupational Safety and Health), 2002b, Internal Dose Reconstruction 

Implementation Guideline, OCAS-IG-002, Office of Compensation Analysis and Support, 

Cincinnati, Ohio.

ORAUT (Oak Ridge Associated Universities Team), 2006a, Technical Basis Document Development, 

Review, and Approval Process, ORAUT-PROC-0031, Rev. 01 PC-1, Oak Ridge, Tennessee, 

February 10.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 45 of 80

ORAUT (Oak Ridge Associated Universities Team), 2006b, Rocky Flats Plant – Occupational Internal 

Dose, ORAUT-TKBS-0011-5, Rev. 01-A, Oak Ridge, Tennessee.

ORAUT (Oak Ridge Associated Universities Team), 2006c, Rocky Flats Plant - Occupational Medical 

Environmental Dose, ORAUT-TKBS-0011-4. Rev. 01-A, Oak Ridge, Tennessee.

ORAUT (Oak Ridge Associated Universities Team), 2006d, Rocky Flats Plant – Occupational 

External Dose, ORAUT-TKBS-0011-6, Rev. 01-A, Oak Ridge, Tennessee.

Putzier, E. A., 1982, The Past 30 Years at Rocky Flats Plant, Rockwell International Energy Systems 

Group, Rocky Flats Plant, Golden, Colorado, November.

RFETS (Rocky Flats Environmental Technology Site), 1981–2005 Occurrence Reports, available at 

Front Range Community College Rocky Flats Reading Room, Westminster, Colorado. 

RFETS (Rocky Flats Environmental Technology Site), 2006a, Total Project Summary Reports for 

2001 through 2005, available at www.rfets.gov, Project Reporting.

RFETS (Rocky Flats Environmental Technology Site), 2006b, “Historical American Engineering 

Record at Rocky Flats Environmental Technology Site,” available at 

http://192.149.55.183/HAER/haer.htm

United Steelworkers of America Local 8031(USWA 8031), 2005. Untitled letter to NIOSH Office of 

Compensation Analysis and Support with attached SEC petition OMB#0920-0639, United

Steel Workers of America Local 8031, Golden, Colorado, February 15.

Voillequé, P. G, 1999a, Estimated Airborne Releases of Plutonium During the 1957 Fire in Building 

71, RAC Report 10-CDPHE-RFP-1999-FINAL, Radiological Assessments Corporation, 

Neeses, South Carolina, August.

Voillequé, P. G, 1999b, Estimated Airborne Releases of Plutonium During the 1969 Fire in Buildings 

776-777, RAC Report 9-CDPHE-RFP-1999-FINAL, Radiological Assessments Corporation, 

Neeses, South Carolina, August.

Voillequé, P. G, 1999c, Review of Routine Releases of Plutonium in Airborne Effluents at Rocky Flats, 

RAC Report 6-CDPHE-RFP-1998-FINAL, Radiological Assessments Corporation, Neeses, 

South Carolina, August.

Weber, J. M., A. S. Rood, H. R. Meyer, and J. E. Till, 1999, Development of the Rocky Flats Plant 903 

Area Plutonium Source Term, RAC Report 8-CDPHE-RFP-1998-FINAL (Rev. 1), Radiological 

Assessments Corporation, Neeses, South Carolina, August.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 46 of 80

GLOSSARY

alloy

A substance composed of two or more metals blended together.

alpha particles

Positively charged particles of discrete energies emitted by certain radioactive materials; alpha 

particles usually expend their energy in short distances and will not usually penetrate the outer 

layer of skin; they are a significant hazard only when taken into the body where their energy Is 

absorbed by tissues.

U.S. Atomic Energy Commission

Original agency established for nuclear weapons and power production; a predecessor to the 

U.S. Department of Energy.

beta radiation

Radiation consisting of charged particles of very small mass (i.e., the electron) emitted 

spontaneously from the nuclei of certain radioactive elements. Most (if not all) of the direct 

fission products emit beta radiation. Physically, the beta particle is identical to an electron 

moving at high velocity.

curie

A special unit of activity. One curie equals 3.7 × 1010 nuclear transitions per second.

criticality

A self-sustaining nuclear fission reaction.

dose equivalent (H)

The product of the absorbed dose (D), the quality factor (Q), and any other modifying factors. 

The special unit is the rem. When D is expressed in Gy, H is in sieverts (Sv). 

(1 Sv = 100 rem.)

dosimeter

A device used to measure the quantity of radiation received. A holder with radiation-absorbing 

elements (filters) and an insert with radiation-sensitive elements packaged to provide a record 

of absorbed dose or dose equivalent received by an individual. (See albedo dosimeter, film 

dosimeter, neutron film dosimeter, thermoluminescent dosimeter.) 

dosimetry

The science of assessing absorbed dose, dose equivalent, effective dose equivalent, etc., 

from external or internal sources of radiation. 

dosimetry system

A system used to assess dose equivalent from external radiation to the whole body, skin, or 

extremities. This includes the fabrication, assignment, and processing of dosimeters as well 

as interpretation and documentation of the results.

exchange period (frequency)

Period (weekly, biweekly, monthly, quarterly, etc.) for routine exchange of dosimeters.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 47 of 80

exposure 

As used in the technical sense, exposure refers to a measure expressed in roentgens (R) of 

the ionization produced by photons (i.e., gamma and X-rays) in air. 

field calibration

Dosimeter calibration based on radiation types, intensities, and energies in the work 

environment.

film

In general, a "film packet" that contains one or more pieces of film in a light-tight wrapping. 

When developed, the film has an image caused by radiation that can be measured using an 

optical densitometer.

film density

See optical density. 

film dosimeter

A small packet of film within a holder that attaches to a wearer.

fission

The splitting of a heavy atomic nucleus, accompanied by the release of energy.

fissionable

Material capable of undergoing fission.

gamma rays

Electromagnetic radiation (photons) originating in atomic. Physically, gamma rays are 

identical to X-rays, the only essential difference being that X-rays do not originate in the 

nucleus. 

HEPA filter

High-efficiency particulate air filter; a dense filter capable of removing a high percentage of 

particulate material from an air flow.

hydrofluorination

Chemical conversion to a form containing fluorine.

ionizing radiation

Electromagnetic or particulate radiation capable of producing charged particles through 

interactions with matter.

isotope

Elements having the same atomic number but different atomic weights; identical chemically 

but having different physical and nuclear properties. 

minimum detectable activity

Limit of radionuclide activity detection for measurements of specific types and energies of 

radiation. 

neutron

A basic particle that is electrically neutral weighing nearly the same as the hydrogen atom.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 48 of 80

neutron, fast

A neutron with energy equal or greater than 10 keV.

neutron, intermediate

A neutron with energy between 0.5 keV and 10 keV.

neutron, thermal

Strictly, a neutron in thermal equilibrium with surroundings. In general, a neutron with energy 

less than about 0.5 eV.

neutron film dosimeter

A film dosimeter that contains a Neutron Track Emulsion, type A, film packet.

Nuclear Track Emulsion, Type A (NTA)

A film that is sensitive to fast neutrons. The developed image has tracks caused by neutrons 

that can be seen by using an appropriate imaging capability such as oil immersion and a 

1000X-power microscope or a projection capability.

open window

Designation on film dosimeter reports that implies the use of little (i.e., only security credential) 

shielding. Commonly used to label the film response corresponding to the open window area. 

operating area

Designation of major onsite operational work areas.

optical density

The quantitative measurement of photographic blackening; density defined as D = Log10 (Io/I).

oralloy

Enriched uranium (containing 0.7 to 93% 235U) named for “O”ak “R”idge alloy.

pencil dosimeter

A type of ionization chamber used by personnel to measure radiation dose. The results can 

be labeled as “Pen” doses. Other names include pencil, pocket dosimeter, pocket pencil, 

pocket ionization chamber. 

personal dose equivalent Hp(d)

Represents the dose equivalent in soft tissue below a specified point on the body at an 

appropriate depth (d). The depths selected for personnel dosimetry are 0.07 mm and 10 mm 

for the skin and body, respectively. These are noted as Hp(0.07) and Hp(10), respectively. 

photon

A unit or "particle" of electromagnetic radiation consisting of X- or gamma rays. 

pit

Nuclear weapon core, made of fissionable material.

radiation

Alpha, beta, neutron, and photon radiation. 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 49 of 80

radioactivity

The spontaneous emission of radiation, generally alpha or beta particles, gamma rays, and 

neutrons from unstable nuclei.

radionuclide

A radioactive isotope of an element, distinguished by atomic number, atomic weight, and 

energy state. 

rem

A unit of dose equivalent equal to the product of the number of rad absorbed and the quality 

factor.

Roentgen (R)

A unit of exposure to gamma (or X-ray) radiation. It is defined precisely as the quantity of 

gamma (or X-) rays that will produce a total charge of 2.58 × 10-4 coulomb in 1 kg of dry air. 

An exposure of 1 R is approximately equivalent to an absorbed dose of 1 rad in soft tissue for 

higher (~>100 keV) energy photons.

scrub or salt scrub

The molten salt process was used to separate metallic plutonium from americium, and then a 

molten salt scrub process was used to remove remaining actinides (americium and residual 

plutonium) from the salt.

shallow absorbed dose (Ds) 

The absorbed dose at a depth of 0.007 cm in a material of specified geometry and 

composition.

shallow dose equivalent (Hs) 

Dose equivalent at a depth of 0.007 cm in tissue.

shielding

Any material or obstruction that absorbs (or attenuates) radiation and thus tends to protect 

personnel or materials from radiation.

sievert (Sv)

The SI unit for dose equivalent. (1 Sv = 100 rem.)

silver shield(s)

The 1-mm-thick shields covering the film packet in early personnel film dosimeters. 

site returns

Weapons components that have been retired and returned for disassembly and recovery of 

materials.

skin dose

Absorbed dose at a tissue depth of 7 mg/cm2

. 

thermoluminescence

Property of a material that causes it to emit light as a result of being excited by heat.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 50 of 80

thermoluminescent dosimeter (TLD)

A holder containing solid chips of material that when heated will release stored energy as light. 

The measurement of this light provides a measurement of absorbed dose. 

transuranic

An element with an atomic number greater than uranium (92); all transuranic elements are 

radioactive and are produced artificially.

trigger

Fissionable core of nuclear weapon, used to trigger fusion energy release. 

whole-body dose

Commonly defined as the absorbed dose at a tissue depth of 1.0 cm (1000 mg/cm2

); however, 

also used to refer to the recorded dose.

X-ray

Ionizing electromagnetic radiation of external nuclear origin.
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 51 of 80

Buildings 122 and 122S

1953 Building constructed. Use designated as medical.

Building 218

Building 218 was actually two 10,000-gal, aboveground, nonradioactive nitric acid storage tanks.

Building 371

Plutonium Recovery Facility

1968 A decision was made to replace the Plutonium Recovery Facility (Building 771) with a 

new building (Building 371).

1972 Construction began on Building 371

1976 Building 371 originally scheduled for startup

1978 Some equipment moved to Building 371

1981 Pilot-scale operations conducted. Due to engineering design problems, production 

processes in this building never operated beyond pilot scale. Plutonium recovery 

(electrorefining) operations remained in Building 771.

1982–1989 No accidents of any significance occurred in this building. In addition, effluent 

emissions were most likely of little significance to the offsite population because this 

building only ran on a pilot-scale basis. Monitoring data for radionuclides were 

available for the life of this building. Emissions data are available for tritium, 238Pu, 

239/240Pu, 241Am, 233/234U, and 238U through 1989.

Building 374

Process Waste Treatment Facility

1978 Building brought on line as the process waste treatment facility for many of the 

production buildings. Emissions data available for tritium, 238Pu, 239/240Pu, 241Am, 233/234U, and 238U through 1991.

1980 Second stage of HEPA filters added.

1986–1988 An increase in waste load.

1988–1989 Condensate from the evaporator went to the cooling tower and was discharged to 

Pond B5. In 1989 this discharge was remedied by not allowing the cooling tower to 

overflow.

1991 The waste treatment facility was supporting the cleanup of the solar evaporation ponds 

and processing waste for Buildings 122, 123, 443, 444, 460, 559, 707, 774, 776, 778, 

779, 865, 881, 883, and 889. 

ATTACHMENT A

ROCKY FLATS BUILDINGS AND OPERATIONS

Page 1 of 12
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 52 of 80

Building 439

Modification Facility

1971 Building constructed. Building 439 houses a machine shop, upholstery shop, battery, 

and office space for Building 439/440 support personnel. No radionuclides were 

known to have been handled here.

Building 440

Fabrication Facility

1971 Building constructed. Building 440 was a fabrication facility in which rebuild and rework 

operations to modify and maintain DOE vehicles and rail cars were performed. 

Operations in the building included metalworking, painting, electrical fabrication, and 

assembly. No radioactive material is known to have been present.

Buildings 444, 445, 450, and 455

Depleted Uranium and Beryllium Metallurgy

1953 Building 444 came on line in August, beginning DU processing.

1957 Building 445 added.

1958 Beryllium operations began in Building 444. Blanks received from commercial supplier 

were machined.

1968 Buildings 444 and 445 connected.

1980 Beryllium casting ended.

1981 Production plating laboratory began operations.

1983 Construction of new filter system for Building 444.

1984–1985 New filter system came on line.

1987 Titanium stripping began.

1989 Uranium foundry shutdown

1990 Production plating lab shut down after a fire

Building 450. Date of construction unknown. Building 450 housed the exhaust filter plenum and 

exhaust fans that handled a major portion of the air exhausted from Building 444. The plenum was 

comprised of a demister section and two stages of HEPA filters. Each stage contained 192 HEPA 

filter units mounted 32 units wide by 6 units high. Three exhaust fans pulled the exhaust air through 

the filter plenum and discharged the air through vent 200 to the atmosphere. Additional facility 

history/equipment modification details are not available.

Building 455. Date of construction unknown. This building was an exterior exhaust filter plenum 

consisting of a demister section and two stages of HEPA filtration. The plenum served the production 

ATTACHMENT A

ROCKY FLATS BUILDINGS AND OPERATIONS

Page 2 of 12
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 53 of 80

plating laboratory in Building 444. Each stage contained 16 HEPA filter units mounted 4 units high by 

4 units wide. The exhaust fan for the plenum exhaust system was mounted on the roof of Building 

444. The fan discharged through vent 82 to the atmosphere.

Foundry. Eight vacuum induction furnaces were used to produce ingots from scrap DU, DU alloys, 

silver, aluminum, and copper. Casting processes produced small quantities of particulates from mold 

coating compounds and metal oxidation reactions. All off-gases discharged through the Building 44 

exhaust system to the Building 450 exhaust filter plenum vent 200. Particulate emission control 

consisted of two stages of HEPA filtration.

Mold Cleaning. Graphite molds used in the foundry area in Building 444 for casting ingots were 

manually cleaned using wire brushes and other hand tools. The molds were recycled for reuse. 

Residual material in the mold after ingot removal included Y2O3, DU oxide, graphite, and trace 

quantities of iron, silica, and other cast metals. This material was collected and transferred by house 

vacuum to a cyclone collector in the Building 444 Utilities Area. The cyclone collector was 85% 

efficient in removing particles greater than 15 microns. According to Plant personnel, approximately 

5% of the material was less than 15 microns. Particulates from mold cleaning discharged through 

vent 200 after passing through a vacuum cyclone separator and two stages of HEPA filtration.

Robot Crucible Cleaning. A robot device in Building 444 cleaned the graphite crucibles used for

heating and melting metals in foundry furnaces. The removed residue contained DU oxide with trace 

amounts of iron, silica Y2O3, graphite, and other cast metals from the crucible. Controls consisted of 

the cyclone separator and two stages of HEPA filtration.

Depleted Uranium Machining. DU machining operations in Building 444 included turning, facing, 

boring, milling, and sawing using numerically controlled lathes and conventional machine tools. Parts 

were fabricated from DU, DU alloy, DU with trace amounts of iron, silica, aluminum, and stainless 

steel.

Buildings 447, 448, and 451

1956 Building 447 constructed. Manufacturing building for a variety of uranium and beryllium 

parts either for production or special orders.

1962 Building 448 constructed. Shipping, receiving, and storage building. Handling of 

radioactive materials not indicated in information reviewed.

1983 Construction of a new filter system for Building 447.

Building 451. Exhaust Filter Plenum Building served processes and facilities in Buildings 447 and 

448.

Electron Beam Welding. An electron beam welder was used for welding vanadium, beryllium, 

aluminum, DU, and stainless steel. Welding operations were performed inside a vacuum chamber.

Electrochemical Milling Operations (ECM). The ECM machine was used for a variety of production 

and special-order jobs. Some work involved milling tungsten, brass, copper, aluminum, and DU.

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Vacuum Arc Melt Furnace. The vacuum arc melt furnace was used to melt material for casting 

consumable electrodes in 6-in. and 8-in. diameter copper molds. The metals melted include DU, and 

DU alloy with 6% niobium. The molds could be up to 5 ft long.

Chip Roaster. The chip roaster was used to oxidize DU scrap metal. The chip roaster was a four-tier, 

single-chamber, vertical roaster.

Building 460

Consolidated Manufacturing Facility

1984 Building constructed. This building was a non-nuclear facility for war reserve and 

special-order parts and assemblies.

Building 549

1957 Building constructed. This building contained the alarm systems.

1991 This building was used exclusively as an electrical maintenance shop and general 

staging support.

Building 559 and 561

Plutonium Analytical Laboratory

1968 Building Constructed. Plutonium Analytical Laboratory. The building contained 

laboratory facilities for conducting spectrochemical, chemical, and mass spectrometric 

analyses. Provided analytical support to SNM management projects.

1973 Building 561 constructed. This building housed the exhaust plenums for Building 559.

Metals, liquids, oxides, oils, and sludges were analyzed for uranium content.

Plutonium Oxidation. Plutonium scraps and oxides remaining after sample analyses were oxidized in 

one of two gloveboxes prior to shipping the PuO2 to another process on the Plant. Scrap and oxide 

from all processes were collected in the two gloveboxes, and the oxidation process was run as 

needed (about once a month).

Building 566

Laundry Facility

Construction date unknown. This building was designed as a laundry facility for clothing and 

respirators contaminated with radioactive materials. 

Building 701

Waste Treatment R&D Facility

1965 Building constructed. Pilot Plant Development. Building 701 was an R&D facility used 

to design, build, and evaluate bench-scale and pilot-scale waste handling and 

treatment processes.

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Building 705

Coatings Laboratory

1966 Building Constructed. This building included coatings laboratories and associated 

offices. No evidence of radioactive materials use in Bldg. 705 was found.

– Vapor Deposition

– Beryllium Vapor Deposition

– Parts Cleaning

– Beryllium Parts Cleaning

– Polishing

– Sand Blasting

– Water Cooling

Building 707

Plutonium Fabrication/Pyrochemical Operations

1972 Construction completed. This building provided metallurgical support in the form of 

foundry and casting operations, as well as product assembly. The machining and 

foundry operations for plutonium came from Building 776 after the 1969 fire. Plutonium 

was stored in the building on an interim basis.

Plutonium Fabrication/Pyrochemical Operations. This building contained foundry and casting 

operations and products assembly.

Module A–Casting Operations. Carbon tetrachloride was used to clean interior glovebox walls where 

casting furnaces were located in which plutonium ingots were made. 

Module J–Casting Operations. Plutonium ingots were made.

Module K–Casting Operations and Stacker Retriever. This operation stored and retrieved plutonium 

metal for distribution to other processes. Metal was weighed, melted in a furnace, and formed into 

ingots.

Module B–Rolling and Forming. This process involved the forming and thermal treatment of 

plutonium metal ingots.

Module C–Briquetting. Metal turnings from Module C machining process and Module B scrap cutters 

were put in metal baskets and dipped in five carbon tetrachloride baths.

Module C–Machining Operations. Plutonium parts were machined.

Modules C and D–Inspection. Parts were cleaned with carbon tetrachloride. 

Casting Operations–Module A. Plutonium ingots were cast into feed or production ingots in Casting 

Operations. Ingots were transported by enclosed, interconnected chain conveyors from storage to the 

foundry gloveboxes. The ingots were placed in crucibles and melted in electric induction furnaces, 

which operated under vacuum. Metal was poured through a funnel into the molds, which were 

allowed to cool. Crucibles and funnels were scraped clean and reused until worn.

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Casting Operations–Module J. Two types of particulate emissions resulted from operations in this 

module. The first was from plutonium oxidation and the second was from casting operations.

Casting Operations and Stacker Retriever–Module K. Module K contained the stacker retriever, also 

known as the X-Y retriever, and casting furnaces. These operations were performed in an inert 

nitrogen atmosphere. The stacker retriever was used to store and retrieve plutonium metal for 

distribution to other processes in Building 707.

Module E, Assembly Operations. Cleaning of plutonium parts.

Module F, Assembly-Superdry. Cleaning of plutonium parts before they were assembled and welded 

into a weapons product.

Module G, Assembly-Welding and Cleaning. Ultrasonic cleaner used to clean plutonium parts 

following welding.

Module G, Assembly-Electron Bombardment Brazing/ Scanning. Cleaning of waste materials 

deposited on the walls of a bell jar during brazing of metals in the jar

Module H Assembly Testing. Cleaning parts prior to testing.

Modules D, E, and G. Assembly ultrasonic cleaners.

Room 173, Radiography. Cleaning plutonium parts prior to radiography (X-ray examination of parts).

Module D, Weighing. Cleaning prior to weighing of parts.

Module E, Eddy Current Testing. To check the depth of weld penetration on plutonium parts moved 

to and from gloveboxes.

Weld Scanners and Fluorescent Penetrant Operations. Area used to qualify welds on plutonium 

parts.

Module D, Production Control Operations. Cleaning plutonium parts following grit blasting.

Modules D and G, Calibration Laboratory. Cleaning gauges before precision measurements.

Building 771

Plutonium Recovery Operations

1953 Building constructed. The principal operation of Building 771 was the recovery of 

plutonium from plutonium-bearing residues.

1957 Americium line started.

1958 Carbon tetrachloride distilled out of the cutting oil and plutonium recovered from solids. 

The cutting oil and carbon tetrachloride mixture came from plutonium machining in 

Building 776.

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1958–1988 Incinerator used for the recovery of fissile material.

1953–1959 PUREX process used for plutonium purification.

1959 Began using ion exchange for plutonium purification.

1968 Caustic scrubber installed.

1963–1975 Ammonium thiocyanate used for recovery of americium.

1975–1980s Oxalate precipitation process used for recovery of americium.

Early 1980s Discontinued americium purification but not recovery.

Building 771 was designed for plutonium recovery from scrap or residue materials. Recovery 

operations were terminated in 1989. The facility was also used for the interim storage of large 

quantities of SNM and waste; laboratory analyses; HEPA filter counting; low specific activity counting; 

and conduct of risk reduction activities. The building also was to solidify ion exchange resins through 

cementation and utilized microwave vitrification for solid residue treatment.

Dissolution. Dissolution processes were all similar in concept. The equipment consisted of a series 

of cascade dissolver vessels. Plutonium-bearing material was fed into the first dissolver at a 

controlled rate by a special screw feeder.

Feed Evaporation. Feed evaporation was used to concentrate some solutions from previous 

operations. Concentration of these solutions was necessary to yield precipitation feed of an 

acceptable plutonium concentration.

Peroxide Precipitation. The peroxide precipitation process converted the plutonium pit in solution to a 

solid form.

Chemical Technology. Plutonium chemistry technology in Building 771 supported and developed 

improved methods for recovering, separating, and purifying actinides from acidic streams.

Calcination. The calcination process converted PuO4 to PuO2 and drove out residual water and 

HNO3, leaving a dry, powdered product. The primary contaminant released from calcination was 

PuO2 particulates.

Hydrofluorination. Plutonium oxide was converted to plutonium tetrafluoride (PuF4) in a continuous 

rotary-tube hydrofluorinator.

Plutonium Oxidation. Plutonium oxidation converted pure plutonium metal, which is pyrophoric, to a 

more stable PuO2. The PuO2 was used as a feed to the dissolution operation.

Plutonium Metallurgy and Research and Air Emissions. The plutonium metallurgy group assisted the 

design agency and Plant production in the development of processes that required metallurgical 

production of materials and related techniques. All plutonium metallurgy operations were conducted 

in gloveboxes.

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ROCKY FLATS BUILDINGS AND OPERATIONS

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Building 774

Process Waste Treatment Facility

1953 Building constructed to support Building 771. Originally designed as a nuclear waste 

packaging facility; used for low-level liquid waste treatment operations. Modifications 

and additions in 1963, 1965, 1966, 1967, 1970, and 1974.

1981 Converted to storage for Building 771 (drums).

Radioactive Decontamination Treatment. Nitric acid was used in the first stage of this process. This 

caustic precipitation process reduced plutonium and americium concentrations.

Caustic Precipitation. This process was the first stage in radioactive decontamination treatment. It 

was designed to reduce the plutonium and americium concentrations.

OASIS (organic and sludge immobilization system). TRU waste from 707 and 776/777. 1,1,1-

trichloroethane (TCA), oils mixed with carbon tetrachloride were solidified with gypsum cement in a 

glovebox.

Buildings 776 and 777

Assembly and Manufacturing Buildings

1957 Buildings 776 and 777 constructed. Building 776: Manufacturing building; Building 

777: Assembly Building. Assembly operations transferred from Building 991.

1958 First significant machining of plutonium begins using cutting oil, followed by washing 

with carbon tetrachloride.

1969 Fire in Building 776 on May 11, 1969.

1972 Operations in Building 776 transferred to Building 707. Building 776 converted to 

waste storage and waste size reduction. Building 776 housed drums containing 

plutonium residue and supported drum venting activities to prevent the buildup of 

hydrogen gas.

1957–1969 Building 776 was the major user of carbon tetrachloride and trichloroethylene at RFP.

This complex was the major plutonium fabrication and assembly facility until 1970. Operations in the 

building were shut down for several months after the 1969 fire and the production operations 

remained shut down. Large amounts of plutonium had been stored at the facility. Operations after 

the 1969 fire included testing and inspection, disassembly of site returns, special projects, plutonium 

recovery, and pyrochemical operations (electrorefining, molten slat extract, direct oxide reduction, and 

salt scrub processes). Waste operations were initiated after the 1969 fire and continued for the life of 

the building. The Supercompactor and size-reduction facilities were used to minimize total volume of 

radioactive waste at the complex.

Building 777. Briquetting. The pressing of plutonium metal machine turnings into pucks using a 

hydraulic press. Turnings were cleaned in metal baskets that are dipped into four CCl4 baths.

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Machining, Rooms 131 and 134A. Parts were cleaned with CCl4 on towels prior to machining.

Inspection, Rooms 130 and 430. Parts were cleaned with CCl4

Disassembly operations. Disassembly occurred in Room 430 and involved the disassembling of 

plutonium parts for further processing in the MSE Operation.

Special Weapons Projects. Special weapons projects performed R&D for fabricating classified parts 

and fitting specialty parts and materials. Plutonium oxidation was conducted to convert pyrophoric 

plutonium residues to nonpyrophoric PuO2. 

Tritium Environmental Control. Tritium was released during the disassembly of some types of 

contaminated parts. The tritium environmental control system removed tritium from gas sampling and 

glovebox exhausts by converting it to tritiated water and desiccating the air stream. Tritium water was 

collected in special containers for further processing.

Building 777. Foundry Operations, Coatings. 

– Disassembly Operations, Room 430. Plutonium parts were disassembled for further 

processing.

– Assembly Superdry, TCA Wash. 

– Ultrasonic Cleaning System, Room 430.

– Ultrasonic Cleaning System, Room 440.

– Plutonium Metallography Laboratory. TCA was used as a cutting agent for grinding with 

carbide grit to cut plutonium.

– Special Weapons Projects. R&D for fabricating classified parts and fitting specialty parts and 

materials.

Building 778

Support Building for Plutonium Processing Buildings

1957 Constructed in 1957, Building 778 was a support building for plutonium 

processing buildings (776, 777, and 707). It was located directly south of 

Buildings 776/777 and was connected to these buildings, as well as Building 707, 

by enclosed walkways. Over its history, Building 778 was mainly used as a 

protective clothing (Anti-Contamination) laundry for all the plutonium process 

buildings, a locker room and shower area, and it housed maintenance shops. 

Building 779

Plutonium Development Building

1965 Building constructed. Building 779 was an R&D facility that supported production. 

Research activities included process chemistry technology, physical metallurgy, 

machining and gauging, joining technology, and hydrating operations. All activities 

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were terminated in 1989 but D&D activities occurred through the mid-1990s. The 

facility had been used for storing SNM and waste. Glovebox activities in support of 

plutonium storage included inspection, metal brushing, and repackaging. Limited 

laboratory activities included waste characterization and minimization, stockpile 

reliability evaluations, and surface analysis. 

Building 865, 867, and 868

R&D of Uranium and Beryllium

1972 Building constructed. Material and process development

Building 867. Date of construction unknown. Contained filter plenums for process exhaust routed 

from Building 865

Building 868. Date of construction unknown. Contained filter plenums for process exhaust routed 

from Building 865.

High Bay. The High Bay area of Building 865 supported production through the R&D of metalworking 

processes. Most work was done with DU, beryllium, copper, tungsten, stainless steel, and other steel 

alloys. Processes included metal casting, machining, rolling, heat-treating, and isostatic pressing. 

Chemical etching and cleaning were performed to prepare the part for inspection and to remove oily 

residues, respectively.

Metallography Laboratory. The Metallography Laboratory in Rooms 102, 106, and 108 conducted 

quality control analyses on metal samples. 

High Bay. Production through R&D of metalworking processes.

Grit Blasters, Room 172. Surface cleaning of parts containing DU.

Building 866

Date of construction unknown. Building 866 was a transfer station. It received wastes from 

Buildings 865 and 889 and transferred them to Building 374.

Building 881

Laboratories, maintenance shops, and Plant support facilities

1953 Building constructed. Building 881 contained laboratories, maintenance shops, and 

Plant support facilities. The original building was designed and built for processing 

enriched uranium. Small quantities of other radioactive materials such as 233U and 

plutonium were also handled in the building.

Buildings 883 and 879

Beryllium and Uranium Machining Facility

1957 Building constructed as a rolling and forming (more commonly referred to as 

machining) facility for both enriched and DU. The building was divided into two sides: 

A side and B side. The A side rolled enriched uranium while the B side rolled DU.

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1966 Enriched uranium operations curtailed at Rocky Flats. The A side of Building 883 was 

converted to beryllium rolling (this process was not enclosed). DU rolling continued on 

the B side.

Mid-1970s Beryllium machining stopped.

1957–1989 Nitric acid commonly used in a 50:50 water/nitric acid mixture for pickling uranium.

1980–1985 Increased processing of DU.

Rolling. Metal ingots, including uranium, were rolled in a rolling mill to reduce thickness and establish 

desirable grain structures. 

Shearing. Uranium plates were mechanically cut into smaller pieces before being shaped in other 

mechanical processes. Uranium scrap was recycled by sending it to Building 444 for recasting.

Blanking/Trepanning. Uranium cut from a sheet with a press and die, and desired shapes were cut 

with trepanning tool. Uranium turnings are placed in a drum and sent to Building 447/448 for uranium 

chip roasting.

Forming. Uranium parts were formed into useful shapes.

Buildings 886 and 875

Nuclear Safety Facility

1965 Building 886 constructed.

— More than 1,600 criticality experiments were performed until 1987. Materials used in 

the experiments (uranyl nitrate metal powder) were reused. Short-lived fission 

products were produced and none were indicated as having been released to the work 

or outdoor environment. The isotopes decayed rapidly and were contained until stable.

Building 910 and Solar Ponds 207A, B, and C 

1957 Solar evaporation pond 207A put into use. Used to store and evaporate low-level 

contaminated waste containing nitrates and radioactive substances (laundry 

wastewater including plutonium and uranium). The history of the ponds is developed 

further in ORAUT (2006c).

1960 Solar Evaporation Ponds 207B and C put into service.

1977 Building 910 (Reverse Osmosis facility) constructed.

Building 991

1951 Construction began on D Plant, now known as Building 991. This was the first building 

constructed at Rocky Flats.

1952 Final product assembly operations conducted

ATTACHMENT A

ROCKY FLATS BUILDINGS AND OPERATIONS

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1958

1960

Building 777 becomes focal point for assembly operations

Building 991 used for storage and R&D. Emissions data for Building 991 include 238Pu, 

239/240Pu, 241Am, 233/234U, and 238U.

Building 995

Air Handling System

1974 Building constructed. Building 985 houses the air handling system that supported the 

underground storage vaults 996, 997, and 999.

Buildings 990, 990a, 995, 988, 228a, 228b (Listed for completeness – no information is readily 

available concerning whether potential for worker exposure existed in these facilities.)

B-990–Pre-Aeration Building 

B-995–Sewage Treatment Facility 

B-988–Tertiary Treatment Pump House

ATTACHMENT A

ROCKY FLATS BUILDINGS AND OPERATIONS

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1. Chemical Operators 

Primary job duties included highly enriched uranium (HEU; Building 881) and plutonium 

(Buildings 771 and 371) metal reprocessing using dissolution, fluorination, calcine, and other wet

chemistry methods to purify metal in preparation for foundry casting operations. Molten salt 

processing (Building 776) was an exceptionally high-neutron process. Other typical job duties 

included waste treatment (Buildings 774 and 374) for waste solutions generated on the Plant.

2. Metallurgical Operators

Primary job duties included casting (Building 881), rolling, and pressing HEU (Building 883), plutonium 

(Buildings 776 and 707), and DU (Buildings 444, 447, and 883). Exposures tended to be less than 

those to Chemical Operators. Machinists, Assemblers, Material Analysts, and Welders had similar 

exposures. Nondestructive Testing Technicians had similar, but probably lower, exposures because 

work was often done on completed pits that inherently shielded the fissile materials. Experimental 

Operators had similar, but probably higher, exposures because they often worked with prototype 

systems or processes that lacked shielding and other radiological controls as the regular production 

processes.

3. Maintenance Workers

Typical trades (i.e., machinists, pipe fitters, welders, carpenters, painters, electricians) had varied 

exposures because they often did more intrusive work on contaminated systems than production 

personnel. Examples of intrusive work included repairing leaks on process lines (pipe fitters), 

refractory replacement in casting and heat treat furnaces (carpenters), repair of mechanical systems 

(machinists), repair of instruments and controllers inside gloveboxes and other systems (electricians), 

and painting over contamination (painters).

4. Support Personnel

Support personnel included clerk packers, metrology technicians, janitors, and handymen who worked 

in process areas but did little or no hands-on work with radioactive materials. Exposures would be 

incidental to working in rooms with process equipment (metallurgical and chemical operations).

5. Analytical Laboratory Technicians

Analytical laboratory technicians worked primarily in Building 559 (plutonium samples) or 881 (HEU or 

DU samples) and probably had lower exposures than operators performing hands-on work with 

significantly larger radioactive material quantities.

6. Site Support Personnel

Stationary operating engineers [SOEs, also known as boiler vent operators (BVOs)], security guards, 

shift managers, and configuration control authority personnel, performed little if any hands-on 

radioactive material or radiation work, but had routine access to process areas. SOEs monitored the 

operation of exhaust systems, waste tanks, and process waste lines. Exposures would be incidental 

to working in rooms with process equipment (metallurgical and chemical operations).

ATTACHMENT B

ROCKY FLATS JOB TITLES AND DESCRIPTIONS

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7. Radiation Control Technicians 

Radiation Control Technicians (RCTs) probably had exposures from supporting production chemical 

and metallurgical processes. Some significant exposures probably occurred during decontamination 

activities, surveys of contaminated areas, upset conditions. There was no hands-on work per se, but 

RCTs generally worked side-by-side with production operators.

8. Decontamination and Decommissioning Workers

D&D work included draining actinide systems, decontamination, size reduction, and removal of 

contaminated equipment, gloveboxes, piping, ductwork, exhaust systems, waste packaging of 

removed equipment, low-level and TRU wastes. Work was often in high (>2,000 dpm alpha, 

removable)-contamination areas with high air concentrations [see ORAUT (2006b) for exposure 

details]. Personal protective equipment (PPE) included air purifying respirators, powered air purifying 

respirators, or PremAir supplied air systems. There were some high exposures due to direct work 

with highly radioactive equipment and contamination events (see ORAUT 2006b and 2006d for 

details).

ATTACHMENT B

ROCKY FLATS JOB TITLES AND DESCRIPTIONS

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LIST OF TABLES

TABLE TITLE

C-1 Partial list of potential hazards associated with various job descriptions 

and locations..........................................................................................................................

PAGE

66

ATTACHMENT C

PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS

Page 1 of 5 
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Much of the data in the following table is taken from DOE Uranium Mass Balance Project report found 

at http://tis.eh.doe.gov/legacy/reports/rockyflats/section1_2.pdf. This table is not a comprehensive

listing of potential radiological exposures associated with Rocky Flats, but is a summary of data 

readily available at this time. 

Table C-1. Partial list of potential hazards associated with various job descriptions and locations. 

Job title Process description Building Type of work Begin End Material

Primary 

radiation 

type

Maximum 

energy

Analytical 

laboratory 

technicians

Sample processing 559 Plutonium sample 

analysis

Pu α 5.16 MeV

Analytical 

laboratory 

technicians

Sample processing 881 HEU or DU sample 

analysis

1953 1965 HEU α 4.6 MeV

Assemblers Pit assembly 700 Handled "War Reserve" 

components

Assemblers Varied–similar to 

Metallurgical 

Operators depending 

on location

Varied Handled metal parts

BVOs Varied–depending on 

location

Varied Monitor exhaust 

systems, waste tanks, 

and process waste lines

Carpenters Varied–depending on 

location

Varied Refractory replacement 

in casting and heat 

treatment furnaces

Chemical 

Operators

Pu metal 

reprocessing

371 Handled contaminated 

reagents

Chemical 

Operators

Waste treatment 374 Handled contaminated 

reagents

Chemical 

Operators

Waste handling 447 Handled contaminated 

reagents

1956 1989 DU α 4.2 MeV

Chemical 

Operators

Component cleaning 447 Handled contaminated 

reagents

1956 1989 DU α 4.2 MeV

Chemical 

Operators

Waste handling 447 Processed waste 

materials

?? ?? DU chips α 4.2 MeV

Chemical 

Operators

Electrolytic decon of 

legacy HEU 

contaminated with Pu

707 Handled contaminated 

reagents

1997 1999 HEU 

Pu

α 4.6 MeV

5.6 MeV

Chemical 

Operators

Pu metal 

reprocessing

771 Handled contaminated 

reagents; Pucontaminated 235U3O8

oxide

1965? 1989 Pu235U oxide α 5.16 MeV

4.2 MeV

Chemical 

Operators

Waste treatment 774 Handled contaminated 

reagents, liquid wastes 

from Building 881

1953 1989 HEU liquid 

wastes

α 4.6 MeV

Chemical 

Operators

Molten salt 

processing

776 Handled contaminated 

reagents

1958 1969 Pu-239 α 5.16 MeV

Chemical 

Operators

Process DU metal 865 Handled contaminated 

reagents

1953 1989 DU α 4.2 MeV

Chemical 

Operators

HEU metal 

reprocessing

881 Handled contaminated 

reagents

1953 1965 HEU α 4.6 MeV

Chemical 

Operators

Uranyl nitrate 

processing

886 Handled contaminated 

reagents

Clerk Packers Varied–depending on 

location

Varied Little hands-on work 

with radioactive 

materials

ATTACHMENT C

PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS

Page 2 of 5 
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Job title Process description Building Type of work Begin End Material

Primary 

radiation 

type

Maximum 

energy

Configuration 

Control Authority 

Personnel

Varied–depending on 

location

Varied Routine access to 

process areas; little 

hands-on work

D&D Workers Varied–depending on 

location

883 Deconned 1993 1995 HEU

DU

α 4.6 MeV

4.2 MeV

D&D Workers Varied–depending on 

location

881 B 

side

Deconned 1965 1967 HEU α 4.6 MeV

D&D Workers Varied–depending on 

location

Varied Drained systems, 

removed contaminated 

equipment. Often in 

high airborne 

contamination areas. 

Often wore PPE, 

including respirators 

with or without supplied 

air.

Electricians Varied–depending on 

location

Varied Repair of instruments 

and controllers inside 

gloveboxes and other 

systems

Experimental 

Operators

Varied–depending on 

location

Varied Operated prototype 

systems, often 

unshielded

Handymen Varied–depending on 

location

Varied Little hands-on work 

with radioactive 

materials

Inspection 

Technicians

Dimensional 

Inspection

881 HEU 1953 1965 HEU α 4.6 MeV

Inspectors Testing 444 Inspected completed 

parts

1953 1994 DU α 4.2 MeV

Janitors Varied–depending on 

location

Varied Little hands-on work 

with radioactive 

materials

Machinists Pit Assembly 700 Handled "War Reserve" 

components

Machinists Machining of Pu parts 776 Operated machining 

equipment

1958 1969 Pu-239 α 5.16 MeV

Machinists Plutonium assembly 777 Drilling, turning, 

polishing

1969 Pu-239 α 5.16 MeV

Machinists Process DU metal 865 Machined DU and DU 

alloys

1953 1989 DU α 4.2 MeV

Machinists 881 Stainless-steel boost 

reservoirs, etc.

1966 1967

Machinists Rod mill grinding 881 Machined HEU parts 1953 1965 HEU α 4.6 MeV

Machinists Rolling, forming, 

machining

881 HEU 1953 1965 HEU α 4.6 MeV

Machinists Presses, rolling mills 883-B Operated machining 

equipment

1957 1965 HEU α 4.6 MeV

Machinists Roll and press DU 

into sheets

883-C Rolling mills, shears 1983 1992 DU α 4.2 MeV

Machinists Rolling, forming, 

machining

883-A Operated machining 

equipment

1957 1992 DU, DU alloys α 4.2 MeV

ATTACHMENT C

PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS

Page 3 of 5 
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Job title Process description Building Type of work Begin End Material

Primary 

radiation 

type

Maximum 

energy

Machinists Varied–similar to 

Metallurgical 

Operators depending 

on location

Varied Repair of mechanical 

systems

Material Analysts Varied–similar to 

Metallurgical 

Operators depending 

on location

Varied Collected metal samples

Metallurgical 

Operators

Casting and 

machining

444 Operated metal 

handling equipment

1956 1989 DU α 4.2 MeV

Metallurgical 

Operators

Casting and 

machining

444 Operated metal 

handling equipment

1980 1984 DU α 4.2 MeV

Metallurgical 

Operators

Casting and cleaning 444 Operated metal 

handling equipment

1967 1969 DU/Mo α 4.2 MeV

Metallurgical 

Operators

Trim and polish DU 

sheets

444 Operated metal 

handling equipment

1953 1989 DU α 4.2 MeV

Metallurgical 

Operators

Roll and press DU 447 Operated metal 

handling equipment

1956 1989 DU α 4.2 MeV

Metallurgical 

Operators

Roll and press Pu 707 Operated metal 

handling equipment

Pu-239 α 5.16 MeV

Metallurgical 

Operators

Roll and press Pu 776 Operated metal 

handling equipment

1958 1969 Pu-239 α 5.16 MeV

Metallurgical 

Operators

Plutonium assembly 777 1969 Pu-239 α 5.16 MeV

Metallurgical 

Operators

Casting, rolling, 

forming, shearing, 

and cleaning

865 Operated metal 

handling equipment

1979 1988 DU, DU alloys α 4.2 MeV

Metallurgical 

Operators

Casting, extruding, 

machining

865 Operated metal 

handling equipment

1979 1988 DU, DU alloys α 4.2 MeV

Metallurgical 

Operators

Process DU metal 865 Machined DU and DU 

alloys

1953 1989 DU α 4.2 MeV

Metallurgical 

Operators

Uranium casting 881 Operated metal 

handling equipment

1953 1965 Uranium α 4.6 MeV

Metallurgical 

Operators

Melting and casting 881 HEU 1953 1965 HEU α 4.6 MeV

Metallurgical 

Operators

Annealing 883-B Operated metal 

handling equipment

1957 1965 HEU α 4.6 MeV

Metallurgical 

Operators

Roll and press DU 

into sheets

883-C Operated metal 

handling equipment

1983 1992 DU α 4.2 MeV

Metallurgical 

Operators

Roll and press DU 883 A 

side

Operated metal 

handling equipment

DU α 4.2 MeV

Metallurgical 

Operators

Roll and press HEU 883 B 

side

Operated metal 

handling equipment

1953 1964 HEU α 4.6 MeV

Metallurgical 

Operators

Roll and press Be 883 B 

side

Operated metal 

handling equipment

1964 ?? Be metal

Metallurgical 

Operators

Casting, rolling, 

forming, shearing, 

and cleaning

883-A Operated metal 

handling equipment

1957 1992 DU, DU alloys α 4.2 MeV

Metrology 

Technicians

Varied–depending on 

location

Varied Little hands-on work

with radioactive 

materials

Nondestructive 

Testing 

Technicians

Testing 444 Tested parts 1953 1994 DU α 4.2 MeV

ATTACHMENT C

PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS

Page 4 of 5 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 69 of 80

Job title Process description Building Type of work Begin End Material

Primary 

radiation 

type

Maximum 

energy

Nondestructive 

Testing 

Technicians

Tensile testing, etc. 447 Tested parts 1956 1989 DU α 4.2 MeV

Nondestructive 

Testing 

Technicians

Varied–depending on 

location

700 Sampled completed pits

Nondestructive 

Testing 

Technicians

Casting, extruding, 

machining

865 Operated metal 

handling equipment

1979 1988 DU, DU alloys α 4.2 MeV

Nondestructive 

Testing 

Technicians

Testing 881 HEU 1953 1965 HEU α 4.6 MeV

Nondestructive 

Testing 

Technicians

Varied–depending on 

location

Varied Sampled completed pits

Painters Varied–depending on 

location

Varied Paint over 

contamination

Pipefitters Varied–depending on 

location

Varied Repair leaks on process 

lines

RCTs Varied–depending on 

location

Varied Monitoring in support of 

chemical and 

metallurgical processes; 

exposures similar to 

Chemical and 

Metallurgical Operators

Security Guards Varied–depending on 

location

Varied Routine security patrols

Shift Managers Varied–depending on 

location

Varied Routine access to 

process areas; little 

hands-on work

SOEs Varied–depending on 

location

Varied Monitor exhaust 

systems, waste tanks, 

and process waste lines

Welders Welding 444 Welded parts as 

necessary

1953 1994 DU α 4.2 MeV

Welders Electron-beam, 

tungsten-inert gas 

welding

447 Welded parts as 

necessary

1956 1989 DU α 4.2 MeV

Welders Plutonium assembly 777 Welding, brazing 1969 Pu-239 α 5.16 MeV

Welders Varied–similar to 

Metallurgical 

Operators depending 

on location

Varied Welded metal parts

ATTACHMENT C

PARTIAL LIST OF POTENTIAL HAZARDS ASSOCIATED 

WITH VARIOUS JOB DESCRIPTIONS AND LOCATIONS

Page 5 of 5 
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 70 of 80

LIST OF TABLES

TABLE TITLE

D-1 Operational accidents and incidents at Rocky Flats Plant ......................................................

PAGE

71

D-2 Incidents at Rocky Flats Plant reported in occurrence reports 1981–2005 ............................. 74

D-3 Incidents at Rocky Flats Plant reported in the quarterly total project 

summary reports, April 2003 to December 2005 .................................................................... 80

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 1 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 71 of 80

Table D-1. Operational accidents and incidents at Rocky Flats Plant. 

Date Location Description [exposure details–see also ORAUT (2006b)]

Nov 21, 1952 Not specified Boiler explosion (disruptive force, no known radionuclide involvement) 

June 14, 1957 Not specified Explosion from chemical reaction (3.2 μg Pu lodged in finger)

Sept 11, 1957 Bldg 771, Rm 180 Fire in a manufacturing building; Pu airborne release.

Oct 25, 1961 Not specified Boiler explosion (disruptive force, no known radionuclide involvement)

Apr/June 1962 Not specified Involved internal Pu exposures to three chemical operators

Mar 16, 1963 Not specified Substation failure due to high-velocity winds and fire (none)

Mar 19, 1963 Not specified Failure of engine in building’s compressor house (none)

Apr 23, 1963 Not specified Contamination from nitric acid spill (none)

June 20, 1963 Not specified Contamination leak and spill in line carrying high-level Pu solution 

(none) 

July 1963 Bldg 771 Filtrate recovery box fire; direct readings of up to 25,000 cpm 

measured from respirator filters.

Feb 1964 Beryllium Shop Fire in Aero-Tech unit attributed to oil that then caused Be oxidation 

June 12, 1964 Building 776 Chemical explosion in glovebox (Pu lodged in finger, thumb).

Sept 25, 1964 Bldg 771, 

Rm 180-A

Americium explosion. Stored Am in solution and in oxide forms from 

Lawrence Livermore National Laboratory. No exposures.

Dec 21, 1964 Bldg 771 Stack Abnormal concentration of material released from Bldg 771 stack 

during latter part of December.

Mar 19, 1965 Not specified Glove failed in a glovebox, releasing Pu resulting in measured lung 

deposition, one worker.

Feb 26, 1965 Not specified Pu released from defective plastic bag. One worker exposed via 

inhalation and skin. Lung burden estimate is 0.02 μCi.

Apr 8, 1965 Not specified Inspected parts knocked off shelf (none)

May 1, 1965 Not specified 3 DU sheets destroyed by burning due to improper labeling 

(approximately 60 kg DU)

May 5, 1965 Roadway Box H-22 was removed from Bldg 76. Contaminate oil leaked from 

box onto roadway between Bldg 76 and waste storage area south of 

Bldg 51 (no exposure reported).

May 6, 1965 Not specified Product feed sprayed out of loose flange, decontamination of three 

workers, details unavailable.

Oct 15, 1965 Bldg 777, Rm 130 

and Bldg 776

Glovebox drain fire releasing Pu resulting in measured lung 

depositions, 10 workers known exposed (up to 400 might have been 

exposed)

Nov 9, 1965 Not specified Glovebox fire (12 skin decontaminations; no significant internal 

exposures)

Nov 27, 1965 Not specified Wind damage to building roof (none)

Jan/Mar 1967 Not specified Pu and Am residues accumulated in a fluorinator glovebox and 

required moving. Resulted in three worker exposures, details 

unavailable.

Jan/Mar 1967 Not specified A process operator handled large Pu charges and castings and large 

amounts of material containing Am-241

Apr 5, 1967 Not specified Employee fell from a tractor, broke leg, died 5 days later. No known 

radionuclide exposures.

Apr/June 1967 Not specified Three employees on the Am line, fluorinator, and oxide dissolution. 

Significant exposures (see ORAUT 2006b).

July/Sept 1967 Not specified A DU-Pu-Mo alloy was processed as normal Pu but high gamma 

readings were reported. Details unavailable – 7 external exposures.

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 2 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 72 of 80

Date Location Description [exposure details–see also ORAUT (2006b)]

Sept 29, 1967 Not specified Contamination spill from blowout of pipe plug. Nuclide data 

unavailable.

Feb 1968 Tritium release of 600 Ci.

Oct 14, 1968 Not specified An employee inhaled Pu-239 from a fire in a hot waste drum. Details 

unavailable. 

Nov 28, 1968 Bldg 444 Supplied air suits of two workers contaminated by ignition of paper 

filter in compressor. Details unavailable.

Dec. 1968 Not specified Storage area east of nitrate pads contaminated by leaking drums 

containing recoverable solids awaiting processing in Building 71. 

High winds blew drums over (no exposure noted).

Jan 7, 1969 Not specified High wind damage to buildings.

Apr 23, 1969 Not specified Employee showed an unexplained Pu-239 lung burden (0.065 μCi).

May 11, 1969 Bldg 776 Glovebox fire in plutonium processing area. See ORAUT (2006b) for 

details.

June 20, 1969 Not specified Molten metal released into furnace interior. Details unavailable.

July 30, 1969 Not specified Fire in tunnel between buildings. Details unavailable.

July 30, 1969 Not specified Two chemical operators screened Pu residues that caught fire when 

later stored (inhaled or ingested 0.15 – 0.99 μg).

Apr 20, 1970 Not specified Contamination release from a plugged drain line. Details unavailable.

Aug 15, 1970 Not specified Power lead short-circuited to bus bar.

Sept 11, 1970 Not specified Acid leaked from storage tank.

Jan 20, 1971 Not specified A process operator was exposed to Am-241 when removing a canned 

Pu button from a shipping container. Lung count noted 

contamination.

Apr 12, 1971 Not specified Corrosion caused steam condensate line to leak contamination. 

Details unavailable.

Apr 19, 1971 Not specified Contamination spread from reduction furnace gasket failure. Details 

unavailable.

June 15, 1971 Not specified A fire started in a shipment of drummed radioactive waste on its way 

to Idaho and self-extinguished (no exposures).

Aug 22, 1971 Not specified Small container exploded and contamination spread by ignited 

plutonium. Measured lung burdens – two employees.

Sept 2, 1971 Not specified Hole in a barrel liner allowed plutonium oxide to escape into room 

(<4 μCi).

Jan 5, 1972 Not specified Electrical faulting of three main substations due to winds and snow.

Jan 11, 1972 Not specified Cell shrouding of cooling tower blew away.

Apr 10, 1972 Not specified Incinerator glovebox fire. Details unavailable.

Feb 8, 1972 Not specified Incinerator fire and contamination caused by a punctured aerosol can 

(no exposures).

Sept 6, 1972 Not specified Three employees exposed to Pu through a faulty glove on a 

glovebox.

Feb 2, 1973 Not specified Supplied air suits contaminated by ignition of a paper filter in the 

compressor. Details unavailable.

Apr 1973 Not specified Tritium release of 500 to 2,000 Ci to atmosphere and waste streams 

during the processing of metal scrap.

Sept 17, 1973 Not specified Elevated levels of tritium were found in Walnut Creek and Great 

Western.

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 3 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 73 of 80

Date Location Description [exposure details–see also ORAUT (2006b)]

Nov 1973 Bldg 995 Several drums of contaminated soil removed from streambed below 

Bldg 995 outfall. No exposure noted.

Apr 2, 1974 Bldg 707 Control valve release due to filter system design error. Details 

unavailable.

Aug 30, 1974 Bldg 777, Rm 452 Tritium release, 1.5 Ci.

Nov 30, 1975 Not specified Trailer blown over by high winds. Details unavailable.

May 19, 1976 Not specified Contamination of R&D equipment and instruments. Details 

unavailable.

Aug 18, 1976 Not specified Overheating caused coils in induction furnace to melt.

Nov 18, 1976 Not specified Source dropped in office area. Details unavailable.

1996–1997 Bldg 371 Unmonitored exposure of office workers might have occurred; details 

being sought.

Oct 16, 2000 Bldg 771, Rm 186 Air measurements in Room 186 not properly documented from 

Sept 7, 2000, to Oct 16, 2000. Ten workers showed unexpectedly 

high levels of exposure.

Oct 20, 2000 Not specified CAM alarm event. At least one worker exposed.

April 20, 2004 Unspecified An individual was assigned a dose for November 1993 of 1,900 mrem 

committed effective dose equivalent (CEDE), potentially occurring 

from five incidents between June 1986 through Nov 1993; details 

being sought.

Sources: Most of the summaries above were taken from AEC (1975), which was published in late 1975. We have not 

discovered a similar accident summary for later periods, but have decided to incorporate this partial listing. Other sources 

include DOE (1980); McLaughlin, Monahan, and Pruvost (2000); Putzier (1982); United Steelworker of America Local 8031

(2005). 

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 4 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 74 of 80

Table D-2. Incidents at Rocky Flats Plant reported in occurrence reports (RFETS 1981–2005). 

Date of 

occurrence Building/room Details Dose

# Persons 

involved

7/8/1983 –

7/11/1983

Bldg 771, main 

exhaust 

system

Effluent filters on main exhaust duct had elevated, long-lived alpha counts. 

Evaluation of the occurrence through August 1983 led to conclusion that there 

was a discharge to the atmosphere that was not within the ranges expected 

from Bldg 771 Main Plenum but, also, that it was not significant.

Not reported ---

On or about 

12/21/1983 

or 1/9/1984

Probably Bldg 

779, Room 133 

and Bldg 776, 

Room 225

Electrician had body count that showed 1 and 1/2 lung burdens. 15 others 

received body counts but only the electrician had positive results.

5.5% maximum permissible 

lung burden

Up to 16

12/3/1985 Bldg 771, 

Room 164, 

Glovebox 67

Glovebox explosion and fire with injury to technician cleaning the glovebox. 

Source of explosion thought to be acetone. Worker transported to Medical, 

then to a hospital. Contamination levels were “minimal” (500 cpm). Others in 

the room had immediately donned respirators, aided the injured worker, and 

evacuated the room.

500 cpm Pu to injured worker; 

contamination released to 

room not reported. 

At least 1

4/3/1985 Bldg 371, 

Room 3515, 

Glovebox 32

Pu inhalation by a chemical operator Not reported 1, possibly 2

7/17/1985 –

7/18/1985

Bldg 779, 

Room 160, GB 

865 Stationary 

Furnace 1

Furnace released radioactive contamination causing special alpha air monitor 

(SAAM) alarm and smoke room 160 and those nearby had air contamination. 

Not reported 3

8/7/1995 Bldg 707, 

Module K

SAAM alarms; airborne alpha contamination. 835 dpm alpha 9 

9/19/1985 Bldg 771, 

Room 149

Pu release to room environment. Not reported; “negative body 

counts” reported.

3

11/26/1985 Bldg 707, 

modules J and 

K ventilation 

systems

SAAMs alarmed after glovebox was breached. Body counts of the 12 workers 

were reported as background; no report of release quantity. 

Not reported 12

11/6/1986 Bldg 771, 

Room 163, 

Glovebox 115

Release of Pu oxide to room; CAM sounded in Room 163; alpha contamination 

on respirator filters of the 5 workers. 

Not reported 5

1/11/1990 881 Annex 

Plenum 

System

Levels of 1,000 dpm/100 cm2 were found on downstream side of plenum filters 

after filter change and effluent monitoring head change in December 1989. 

Cause determined to be contamination that was liberated from old filters during 

change-out.

Maximum dose to the public 

estimated to be less than 0.3 

mrem and to onsite worker 

less than 25 mrem.

Unknown

1/25/1990 Bldg 771, Port 

17 Line 7

Glove came off the glove change ring, contaminating employee’s arm. 

Employee transferred to Medical for decontamination before returning to work.

1,000 cpm 1 

3/8/1990 Bldg 707, X-Y 

retriever

Two machinists received contamination to head and neck during maintenance 

operation.

Not reported 2 

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 5 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 75 of 80

Date of 

occurrence Building/room Details Dose

# Persons 

involved

3/13/1990 Bldg 771, 

Room 149

One electrician received contaminated hands during maintenance of conduit. Not reported 1

3/20/1990 Bldg 771, 

Room 114

One electrician received contaminated hands during light-bulb change in 

gloveboxes. 

Not reported 1

4/10/1990 Bldg 707 One maintenance worker received contamination on gloves and sleeve during 

safety latch installation on Hydroform Press Ram Assembly.

Not reported 1

4/24/1990 Bldg 776, 

Room 134

RPT found contamination of 1,000 cpm on floor during premaintenance job 

survey. Decontamination was stopped and room deposited for respirator use 

to allow a tour to go through area. Members of tour and five building personnel 

passed within 50 ft of contaminated area, potentially being exposed to airborne 

contamination.

Operational health physics 

department estimated dose to 

be less than 10E-4 mrem. 

More than 5

4/30/1990 Bldg 777, 

Room 131

Operator's hands contaminated during routine housekeeping operations. Not reported 1

5/24/1990 Bldgs 707, 

776/777, 779, 

771/774, 

371/364, and 

991

Noncompliance to filter surveillance: filters were less than 99.5% effective PL101 releases in pCi/m3 1988: 6.1E-5 + 1.4E-4 1989: 9.0E-5 + 1.21E-4 1990: 

2.0E-6 + 2.5E-5 FU-25 releases in pCi/m3 1988: 7.9E-5 +1.71E-4 1989: 4.0E-5 

+ 4E-5 1990: 2.0E-6 + 2.5E-4. 

Pu-239 releases; see details Environmental

April–May 

1990

Pu operations Inadequate posting of respiratory protection requirements resulted in several 

employees entering rooms without respirators; five separate incidents.

Apparently none More than 9

10/11/1991 Plenum 104 One positive inhalation and three skin contamination from working on plenum. 

 

500 to 4,000 dpm on skin. 

Bioassay results not reported 

but one was positive.

4 

12/31/1991 Bldg 707 Hand abrasion with positive wound count received by one construction worker; 

wound decontaminated. Medical requested urine sample. Worker complied 

but results not reported.

0.34 nCi in wound 1

1/29/1992 Bldg 707 Metal working manager (MWM) found to have alpha contamination on both 

hands from a tool toter. MWM was wearing full-face respirator during job. 

MWM reported to Medical for a bioassay kit; results not reported.

4,000 dpm on hands 1 

1/29/1992 Bldg 707, 

Room 167

Four Maintenance personnel found to have contamination on protective 

clothing (3,000 to 5,000 dpm) but not skin. The employees requested bioassay 

kits, although informed that they were not necessary because no skin 

contamination was found. 

3,000-5,000 dpm on 

protective clothing; bioassay 

results not reported. 

4

2/5/1992 Module J RPT detected 4,000 dpm on glovebox during prejob survey and advised 

maintenance personnel to don respirators and leave area. RPT did not know 

that two additional personnel were in module and did not warn them to don

respirators and exit. The two employees were in Module J without respirators 

for about 25 min. The two employees were monitored for contamination and 

issued bioassay kits; no contamination was reported.

None reported 2

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 6 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 76 of 80

Date of 

occurrence Building/room Details Dose

# Persons 

involved

3/11/1992 Bldg 707, 

Module J

Window change on glovebox J60 resulted in SAAM alarm. Workers were 

already wearing full-face respirators and protective clothing. Contamination of 

2,000 dpm was found on SAAM paper. Respirator cartridges had levels of 

14,000 to 20,000 dpm. All personnel were issued bioassay kits as a 

precautionary measure.

Not reported Unspecified 

but at least 4

3/17/1992 Bldg 771, 

Glovebox 228

Employee received puncture wound to hand and possible contamination while 

preparing to perform work on glovebox. Wound count above background on 

two measurements then below background. Employee issued bioassay kit.

Negative 1

4/8/1992 Bldg 707 The EG&G medical director and industrial hygienist self-toured Modules A, B, 

and C without required respiratory protection. They self-reported when they 

discovered the postings. Both received nasal smears (negative) and TLDs 

were taken pending results of bioassays.

Not reported 2 

6/9/1992 Bldg 707, 

Module J, 

Glovebox J-60

Ductwork removal resulted in contamination of personnel and high DAC. SAAM filter = 1,080 DAC 

Bioassays performed but 

results not reported. 

Employee’s hand at 2,000 

dpm; one worker’s respirator 

filter at 1,500 dpm alpha; 

RCT’s respirator filter at 1,000 

dpm.

4 

11/10/1992 Bldg 771, 

Room 180F

Radiological contamination found during survey of Room 182. On 11/11/1992, 

exhaust fixed air sampler for Room 180F had 80% of one DAC (400 dpm). 

Levels of 330 dpm and 366 dpm were found on floor.

None reported Unknown

1/15/1993 Bldg 707, 

Module K

Employee received skin contamination on left palm (alpha contamination of 

1,000 dpm). Employee was successfully decontaminated. No source 

identified.

None reported 1 

7/2/1993 Internal 

Dosimetry

Change in lung count measurements due to a positive analysis; testing 

occurred 8/6/92 and 8/7/92; exposure occurred in 1973. 

11 rem CEDE; 220 mrem 

annual effective dose 

equivalent (EDE)

1

8/18/1995 Bldg 707, 

Module K

2 workers performing decontamination activities when DAC readings indicated 

the need for full-face respirators. Both workers received nasal and mouth 

smears; results indicated potential inhalation exposures.

Not reported; bioassays kits 

were provided. 

2 

9/15/1995 Bldg 883, 

Hydroform 

Press 

During dismantling of a hydroform press, 8,000 dpm of fixed and removable 

alpha detected as well as spikes of Am. Possible that duct had been 

contaminated before use in building because interviews with past employees 

indicated no use of Am in building.

Unknown Unknown

7/18/1997 Bldg 771, 

Room 154

Portable CAM alarm when laboratory personnel were preparing particle size 

samples. No source found. Three workers in area.

Filter = 2,052 dpm alpha 

Worker shoe = 9,000 dpm/ 

100 cm2

3

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 7 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 77 of 80

Date of 

occurrence Building/room Details Dose

# Persons 

involved

7/16/1998 Bldg 779, 

Rooms 152 

and 154

Skin contamination > 2,000 dpm, SAAM alarm at 4 DAC. Up to 6,000 dpm/100 cm2 on 

head and shoulders

3

10/22/1998 Bldg 371 (Pu 

recovery)

Rad worker assigned CEDE above threshold Pu dose received April 1995. 

Source/cause unknown.

6 rem CEDE 1

1/13/1999 Bldg 779, 

Room 137

Positive SAAM during glovebox move. One RCT was present without 

respiratory protection.

9.5 DAC in air up to 100,000 

dpm/100 cm2 in room

At least 1

2/2/1999 Bldg 779, 

Room 133, 

Glovebox 955

D&D worker received laceration to finger while working in glovebox. Worker 

transported to Medical; wound count was 41 nCi. Worker given chelation 

therapy and transported off site for wound treatment involving tendon injury.

CEDE of 3,100 mrem. Organ 

dose equivalent to bone 

surface of 56,000 mrem

1

9/8/1999 Bldg 779 Pu contamination of 6 workers' boots from roof duct chase. All were given 

nasal smears and bioassay kits; results not reported but expected to be 

negative due to wet nature of the contamination.

Up to 12,000 dpm/100 cm2 on 

boots; up to 180,000 dpm/ 

100 cm2 direct and 7,200 

dpm/100 cm2 removable on 

duct chase.

6 

10/26/1999 Bldg 707, 

Module K

CAM and SAAM sounded when a Process Specialist was performing routine 

duties for Pu sizing. Glovebox glove was torn. Worker received 1,000 dpm to 

face, 3,000 dpm on head/hair, and 500 dpm on neck. Three additional workers 

exposed to airborne activity. All 4 issued bioassay kits.

Up to 3,000 dpm on one 

worker; bioassay results not 

reported. 

4 

10/28/1999 Bldg 771, HV1015 D&D worker received skin contamination of up to 40,000 dpm/100 cm2 on arm 

while building a containment around valve HV-1016 on room 146B. Nasal and 

mouth smears taken; fecal sample requested.

Mouth smears were below 

decision level but bioassay 

results not reported.

1 

11/5/1999 Bldg 771, 

Trailer T771H

Clam shells found in plastic bag outside trailer with contamination levels as 

high as 23,700 dpm/100 cm2 fixed and 830 dpm/100 cm2 removable. 

Contamination determined to be Pu. Determined that shells had been in Bldg 

774 in a cargo container.

23,700 dpm/100 cm2 fixed Unknown

11/17/1999 Bldg 707, 

Module A

Two Process Specialists (PSs) were working in Glovebox A10 when a hole 

developed. One PS had Level II potential inhalation and the other had PI less 

than decision level. Eight other PSs were in room at time. 

DAC of 17.44; one PS had 

7,200 dpm on head and 600 

dpm on face and was issued 

bioassay kit.

10

1/24/2000 Bldg 771 On 9/23/99, three workers received routine nasal smears after a room had a 

DAC of 595. Results for one worker indicated potential intake on 10/5/99. 

Bioassay submitted by worker with results of 460 mrem. Additional bioassay 

samples submitted. On 1/19/00, results confirmed intake at 270 mrem.

Unknown 1

3/9/2000 Bldg 771 Routine nasal smears of workers taken on 1/28/00 revealed potential 

contamination on 2/8/00. Bioassay sample was submitted and on 3/9/00 

results indicated an exposure of 110 mrem CEDE for 2000. Worker's 

thermoluminescent dosimeter (TLD) was pulled and, after analysis, worker was 

returned to full work status.

Unknown 1 

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 8 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 78 of 80

Date of 

occurrence Building/room Details Dose

# Persons 

involved

6/8/2000 Bldg 707 Two PSs received skin contamination from hole in glovebox glove. One PS 

had 60,000 dpm on neck and ear; the other had 400 to 600 dpm on shoulders 

neck and face. One worker sent to Medical for additional decontamination. 

One security badge and electronic pocket dosimeter could not be 

decontaminated and were disposed of as required.

Up to 60,000 dpm 2

9/6/2000 Bldg 371, 

Glovebox 1509

One operator received skin contamination on arm of 9,600 dpm during drum 

unloading operations. Worker was issued bioassay kit; results not reported.

9,600 dpm 1

9/7/2000 Bldg 371, 

Room 3408

CAM alarm sounded and contamination on worker of 3,600 dpm found on 

worker's anti-C clothing. Nasal smear was positive and preliminary dose 

estimate was 900 mrem CEDE. Bioassay kit issued.

Preliminary estimate of 900 

mrem 

1

11/30/2000 Bldg 771 Bioassay samples were requested of 11 employees after radiological 

documentation deficiencies were found on 10/16/00. The first bioassay results 

were returned on 11/27/00 and 10 were above the decision level, so a second 

set was requested. At that time, 44 employees who worked in the building 

volunteered to provide samples.

Results of 9 of the original 11 

workers ranged from 6 to 60 

mrem; other results not 

reported.

11+

2/9/2001 Bldg 371 During repair to V-blender in a glovebox, an RCT received 18,000 dpm alpha 

contamination on an anti-C glove. Personnel exited the area. No skin 

contamination was found but two employees were issued bioassay kits based 

on potential inhalation intakes.

Not reported. No CAM 

alarms sounded.

2

2/12/2001 Bldg 371, 

Room 1005 

Spread of radiological contamination occurred in Corridor 1005 from a leaking 

drum identified on 2/9/01. Personnel had accidentally tracked contamination 

from the buffer area through the hallway. Levels of 200,000 dpm alpha were 

found in Room 1115 and 2,500 dpm alpha in Room 1210. Seven employees 

were issued bioassay kits for Pu.

Not reported 7

3/19/2001 Bldg 771 D&D worker received skin contamination of 4,500 dpm/100 cm2 to 220,000 

dpm/100 cm2 from torn glove while performing process piping removal. Worker 

was issued a bioassay kit. Other workers did not receive contamination from 

incident.

100 mrem CEDE to one 

worker

1

7/27/2001 Bldg 707 D&D workers received contamination during glovebox work. All workers in 

area alerted to use full-face respirators. Two workers had skin contamination 

of 198 dpm/100 cm2

. Two workers were required to submit bioassay samples; 

a third worker was not required to submit a sample.

220 mrem CEDE to one 

worker

3

10/3/2001 Bldg 771 Internal dosimetry received bioassay results for a worker from 7/20/01; result 

was internal dose of 460 mrem. Exposure had occurred during swager 

removal from GB205. Two air monitors had alarmed during removal activities. 

Five employees had been sent to internal dosimetry for bioassay samples.

One worker at 460 mrem; one 

worker at 1 mrem; one worker 

at 8 mrem; 2 workers at 0 

mrem. 

5

12/12/2001 Bldg 707 D&D worker had 1,500 dpm on face. Due to potential inhalation intake, worker 

sent to occupational medicine, TLD was pulled, and worker was issued a 

bioassay kit. Lung count was below decision level.

Not reported 1

ATTACHMENT D

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Page 9 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date:

02/01/2007 Page 79 of 80

Date of 

occurrence Building/room Details Dose

# Persons 

involved

1/2/2002 Bldg 771, 

Room 169

Two RCTs entered Room 169 to perform surveys and housekeeping. After 

completing job, CAM alarm sounded in adjacent room. One RCT requested 

nasal/mouth smear with result of 110 cpm. Both RCTs were issued bioassay 

kits. A D&D worker from adjacent area requested and was issued a bioassay 

kit as well. Results for all indicated uptakes of Pu-239/240. (Original incident 

occurred 10/5/01; results issued on 1/2/02.)

One at 1.6 rem CEDE, one at 

240 mrem CEDE, one at 8 

mrem CEDE (but was 

attributed to chronic rather 

than acute exposure). 

3

1/15/2002 Bldg 707, Set 

A-2 and A-10 

Gloveboxes

CAM alarm sounded while personnel were taping metal pieces in gloveboxes. 

Personnel evacuated area. One RCT had 3,000 dpm/100 cm2 on left shoulder 

of anti-C clothing and hair. She was successfully decontaminated. Her TLD 

was pulled and nasal/mouth smears performed on her and six other personnel 

in area. RCT also submitted bioassay samples and had a lung count. Fecal 

bioassay showed Pu uptake of 1 mrem CEDE.

1 mrem CEDE for one worker 7

1/26/2002 Bldg 771 While removing sections of house vacuum in Room 114, liquid dripped onto 

five workers. CAM alarm sounded. Work crew exited area and nasal smears 

were taken from all five workers. Four of the five workers were sent to Internal 

Dosimetry for bioassay analysis and restricted from working in contaminated 

area pending results.

One at 2 mrem CEDE, two at 

1 mrem CEDE, one at 0 

mrem CEDE

5

1/28/2002 Bldg 707 Information received on 1/28/02 from incident of 2/2001. In 2/2001, Internal 

Dosimetry received urine Pu results that were higher than expected for an 

individual. Wound count was requested after other follow-up analyses. Wound 

count results showed dose of 1.4 rem CEDE and 26 rem CEDE to bone 

surface. This intake was assigned for Dec. 2000.

1.4 rem CEDE and 26 rem 

bone surface CEDE

1

3/21/2002 Bldg 707, 

Module C

During removal of a drain line, liquid sprayed out of the line causing multiple 

CAM alarms to sound. Respiratory protection was being worn at the time. All 

15 workers exited area. Two of the 15 workers had skin contamination (2,400 

dpm and 360 dpm). All personnel received precautionary nasal and mouth 

smears. Bioassay kits were issued to the two workers who received skin 

contamination. Others apparently were issued kits as well, because six results 

showed intakes had occurred.

DAC was 1,374, then later 

was 18 (filter may have 

received liquid spray). One at 

120 mrem CEDE. One at 2 

mrem CEDE. Two at 1 mrem 

CEDE. One at 0 mrem 

CEDE. 

15

5/7/2002 Bldg 371, 

Room 3305, 

Glovebox 37

Supervisor received skin contamination of 12,000 dpm/100 cm2 on arm during 

D&D activities. Supervisor was to submit bioassay samples to Internal 

Dosimetry.

12,000 dpm/100 cm2 on skin. 

Bioassay results not reported.

1

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

Page 10 of 11
Document No. ORAUT-TKBS-0011-2 Revision No. 01 Effective Date: 02/01/2007 Page 80 of 80

Table D-3. Incidents at Rocky Flats Plant reported in the quarterly total project summary reports, April 

2003 to December 2005. 

Date Building Description Dose # involved

Third quarter (Q3) 371 Two RCTs received Pu uptakes during connection of an 

intake hose to a B-box contamination control enclosure.

Not reported 2

Q3 2003 371 Fire in glovebox; four firefighters received skin 

contamination.

Not reported 4 

Q4 2003 (July–

September)

707 Zone I duct removal in E module resulted in ventilation 

anomaly and CAM alarms sounded. Module E evacuated; 

contamination was found on the shoes of eight workers and 

in an adjacent corridor. 

500 to 1,000 

dpm of 

removable 

alpha

At least 8

First quarter (Q1) 

2004 (October–

December 2003)

371 D&D worker had 12,000 dpm/100 cm2 on left arm; worker 

was successfully decontaminated on site. No source 

identified.

12,000 

dpm/100 

cm2

1 

Q3 2004 Not 

reported

D&D worker had 11,000 dpm alpha on skin of right knee; 

he was successfully decontaminated at the site.

11,000 dpm 

alpha

1

Q3 2004 Not 

reported

D&D worker received 6,000 dpm skin contamination on 

forehead. He was successfully decontaminated on site.

6,000 dpm 

alpha

1

Q4 2004 371 Two D&D workers received skin contamination during 

piping removal. 

1,200,000 

dpm and 

4,400 dpm

2 

Q4 2004 371 Two D&D workers received skin contamination during floor 

shaving. 

9,200 dpm 

and 400 

dpm

2

Q4 2004 371 RCT detected 6,300 dpm on finger while self-monitoring at 

step-off pad. Source is likely the radiological barrier rope. 

6,300 dpm 1 

Q4 2004 371 RCT received 11,000 dpm skin contamination on chest due 

to holes found in anti-C clothing.

11,000 dpm 1

Q4 2004 707 D&D worker received 2,400 dpm skin contamination on 

right forearm while working in a Standard Waste Box.

2,400 dpm 1

Q1 2005 (October–

December 2004)

Not 

reported

Two events of skin contamination > 1,000 dpm (one in 

October and one in November). No details reported.

>1,000 

dpm/100 

cm2

2

ATTACHMENT D

OPERATIONAL ACCIDENTS AND INCIDENTS AT ROCKY FLATS PLANT

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